all tests passed

MathUtilities.java

@@ -11,7 +11,7 @@ public class MathUtilities {
     * @return sum of `baseValue` and `difference`
     */
    public Integer add(int baseValue, int difference) {
-       return null;
+       return baseValue + difference;
    }
 
    /**
@@ -20,7 +20,7 @@ public class MathUtilities {
     * @return sum of `baseValue` and `difference`
     */
    public Long add(long baseValue, long difference) {
-       return null;
+       return baseValue + difference;
    }
 
    /**
@@ -29,7 +29,7 @@ public class MathUtilities {
     * @return sum of `baseValue` and `difference`
     */
    public Short add(short baseValue, short difference) {
-       return null;
+       return (short) (baseValue + difference);
    }
 
    /**
@@ -38,7 +38,7 @@ public class MathUtilities {
     * @return sum of `baseValue` and `difference`
     */
    public Byte add(byte baseValue, byte difference) {
-       return null;
+       return (byte) (baseValue + difference);
    }
 
    /**
@@ -47,7 +47,7 @@ public class MathUtilities {
     * @return sum of `baseValue` and `difference`
     */
    public Float add(float baseValue, float difference) {
-       return null;
+       return (float) (baseValue + difference);
    }
 
    /**
@@ -56,7 +56,7 @@ public class MathUtilities {
     * @return sum of `baseValue` and `difference`
     */
    public Double add(double baseValue, double difference) {
-       return null;
+       return (double) (baseValue + difference);
    }
 
    /**
@@ -65,7 +65,7 @@ public class MathUtilities {
     * @return difference between `baseValue` and `difference`
     */
    public Integer subtract(int baseValue, int difference) {
-       return null;
+       return baseValue - difference;
    }
 
    /**
@@ -74,7 +74,7 @@ public class MathUtilities {
     * @return difference between `baseValue` and `difference`
     */
    public Long subtract(long baseValue, long difference) {
-       return null;
+       return (long) (baseValue - difference);
    }
 
    /**
@@ -83,7 +83,7 @@ public class MathUtilities {
     * @return difference between `baseValue` and `difference`
     */
    public Short subtract(short baseValue, short difference) {
-       return null;
+       return (short) (baseValue - difference);
    }
 
    /**
@@ -92,7 +92,7 @@ public class MathUtilities {
     * @return difference between `baseValue` and `difference`
     */
    public Byte subtract(byte baseValue, byte difference) {
-       return null;
+       return (byte) (baseValue - difference);
    }
 
    /**
@@ -101,7 +101,7 @@ public class MathUtilities {
     * @return difference between `baseValue` and `difference`
     */
    public Float subtract(float baseValue, float difference) {
-       return null;
+       return (float) (baseValue - difference);
    }
 
    /**
@@ -110,7 +110,7 @@ public class MathUtilities {
     * @return difference between `baseValue` and `difference`
     */
    public Double subtract(double baseValue, double difference) {
-       return null;
+       return (double) (baseValue - difference);
    }
 
 
@@ -120,7 +120,7 @@ public class MathUtilities {
     * @return division of `dividend` by `divisor
     */
    public Integer divide(int dividend, int divisor) {
-       return null;
+       return dividend / divisor;
    }
 
    /**
@@ -129,7 +129,7 @@ public class MathUtilities {
     * @return division of `dividend` by `divisor
     */
    public Long divide(long dividend, long divisor) {
-       return null;
+       return (long) (dividend / divisor);
    }
 
    /**
@@ -138,7 +138,7 @@ public class MathUtilities {
     * @return division of `dividend` by `divisor
     */
    public Short divide(short dividend, short divisor) {
-       return null;
+       return (short) (dividend / divisor);
    }
 
    /**
@@ -147,7 +147,7 @@ public class MathUtilities {
     * @return division of `dividend` by `divisor
     */
    public Byte divide(byte dividend, byte divisor) {
-       return null;
+       return (byte) (dividend / divisor);
    }
 
    /**
@@ -156,7 +156,7 @@ public class MathUtilities {
     * @return division of `dividend` by `divisor
     */
    public Float divide(float dividend, float divisor) {
-       return null;
+       return (float) (dividend / divisor);
    }
 
    /**
@@ -165,7 +165,7 @@ public class MathUtilities {
     * @return division of `dividend` by `divisor
     */
    public Double divide(double dividend, double divisor) {
-       return null;
+       return (double) (dividend / divisor);
    }
 
 
@@ -175,7 +175,7 @@ public class MathUtilities {
     * @return product of `multiplicand` by `multiplier`
     */
    public Integer multiply(int multiplicand, int multiplier) {
-       return null;
+       return multiplicand * multiplier;
    }
 
    /**
@@ -184,7 +184,7 @@ public class MathUtilities {
     * @return product of `multiplicand` by `multiplier`
     */
    public Long multiply(long multiplicand, long multiplier) {
-       return null;
+       return (long) (multiplicand * multiplier);
    }
 
    /**
@@ -193,7 +193,7 @@ public class MathUtilities {
     * @return product of `multiplicand` by `multiplier`
     */
    public Short multiply(short multiplicand, short multiplier) {
-       return null;
+       return (short) (multiplicand * multiplier);
    }
    /**
     * @param multiplicand value to be multiplied
@@ -201,7 +201,7 @@ public class MathUtilities {
     * @return product of `multiplicand` by `multiplier`
     */
    public Byte multiply(byte multiplicand, byte multiplier) {
-       return null;
+       return (byte) (multiplicand * multiplier);
    }
 
    /**
@@ -210,7 +210,7 @@ public class MathUtilities {
     * @return product of `multiplicand` by `multiplier`
     */
    public Float multiply(float multiplicand, float multiplier) {
-       return null;
+       return (float) (multiplicand * multiplier);
    }
 
    /**
@@ -219,7 +219,7 @@ public class MathUtilities {
     * @return product of `multiplicand` by `multiplier`
     */
    public Double multiply(double multiplicand, double multiplier) {
-       return null;
+       return (double) (multiplicand * multiplier);
    }
 
 
@@ -227,14 +227,14 @@ public class MathUtilities {
      * @return true
     */
    public Boolean returnTrue() {
-       return null;
+       return true;
    }
 
    /**
     * @return false
     */
    public Boolean returnFalse() {
-       return null;
+       return false;
    }
 
 }

PredicateUtilities.java

@@ -10,7 +10,7 @@ public class PredicateUtilities {
     * @return true if `x` is greater than `y`
     */
    public Boolean isGreaterThan(int x, int y) {
-       return null;
+       return x > y;
    }
 
    /**
@@ -19,7 +19,7 @@ public class PredicateUtilities {
     * @return true if `x` is less than `y`
     */
    public Boolean isLessThan(int x, int y) {
-       return null;
+       return x < y;
    }
 
    /**
@@ -28,7 +28,7 @@ public class PredicateUtilities {
     * @return true if `x` is greater than or equal to `y`
     */
    public Boolean isGreaterThanOrEqualTo(int x, int y) {
-       return null;
+       return x >= y;
    }
 
    /**
@@ -37,6 +37,6 @@ public class PredicateUtilities {
     * @return true if `x` is less than or equal to `y`
     */
    public Boolean isLessThanOrEqualTo(int x, int y) {
-       return null;
+       return x <= y;
    }
 }

StringUtilities.java

@@ -8,7 +8,7 @@ public class StringUtilities {
      * @return `Hello World` as a string
      */
     public String getHelloWorld() {
-        return null;
+        return "Hello World";
     }
 
     /**
@@ -17,7 +17,7 @@ public class StringUtilities {
      * @return the concatenation of two strings, `firstSegment`, and `secondSegment`
      */
     public String concatenation(String firstSegment, String secondSegment){
-        return null;
+        return firstSegment + secondSegment;
     }
 
     /**
@@ -26,7 +26,7 @@ public class StringUtilities {
      * @return the concatenation of an integer, `firstSegment`, and a String, `secondSegment`
      */
     public String concatenation(int firstSegment, String secondSegment){
-        return null;
+        return firstSegment + secondSegment;
     }
 
     /**
@@ -34,7 +34,7 @@ public class StringUtilities {
      * @return the first 3 characters of `input`
      */
     public String getPrefix(String input){
-        return null;
+        return input.substring(0, 3);
     }
 
     /**
@@ -42,7 +42,7 @@ public class StringUtilities {
      * @return the last 3 characters of `input`
      */
     public String getSuffix(String input){
-        return null;
+        return input.substring(input.length() - 3);
     }
 
     /**
@@ -51,7 +51,7 @@ public class StringUtilities {
      * @return the equivalence of two strings, `inputValue` and `comparableValue`
      */
     public Boolean compareTwoStrings(String inputValue, String comparableValue){
-        return null;
+        return inputValue.equals(comparableValue);
     }
 
     /**
@@ -59,7 +59,7 @@ public class StringUtilities {
      * @return the middle character of `inputValue`
      */
     public Character getMiddleCharacter(String inputValue){
-        return null;
+        return inputValue.charAt((inputValue.length() - 1) / 2);
     }
 
     /**
@@ -67,7 +67,7 @@ public class StringUtilities {
      * @return the first sequence of characters
      */
     public String getFirstWord(String spaceDelimitedString){
-        return null;
+        return spaceDelimitedString.split(" ")[0];
     }
 
     /**
@@ -75,7 +75,7 @@ public class StringUtilities {
      * @return the second word of a string delimited by spaces.
      */
     public String getSecondWord(String spaceDelimitedString){
-        return null;
+        return spaceDelimitedString.split(" ")[1];
     }
 
     /**
@@ -83,7 +83,7 @@ public class StringUtilities {
      * @return an identical string with characters in reverse order.
      */
     public String reverse(String stringToReverse){
-        return null;
+        return new StringBuilder(stringToReverse).reverse().toString();
     }
 
     /**
@@ -91,7 +91,7 @@ public class StringUtilities {
      * @return an identical string with spaces removed.
      */
     public String removeWhitespace(String input){
-        return null;
+        return input.replaceAll("\\s+","");
     }
 
     /**
@@ -99,6 +99,6 @@ public class StringUtilities {
      * @return an identical string with spaces in the front and end removed.
      */
     public String trim(String input){
-        return null;
+        return input.trim();
     }
 }

package.bluej

@@ -8,18 +8,18 @@ dependency2.type=UsesDependency
 dependency3.from=MathUtilitiesTest
 dependency3.to=MathUtilities
 dependency3.type=UsesDependency
-editor.fx.0.height=0
-editor.fx.0.width=0
-editor.fx.0.x=0
-editor.fx.0.y=0
+editor.fx.0.height=697
+editor.fx.0.width=800
+editor.fx.0.x=307
+editor.fx.0.y=100
 objectbench.height=145
 objectbench.width=776
 package.divider.horizontal=0.6
 package.divider.vertical=0.7195571955719557
 package.editor.height=383
 package.editor.width=674
-package.editor.x=29
-package.editor.y=132
+package.editor.x=189
+package.editor.y=124
 package.frame.height=600
 package.frame.width=800
 package.numDependencies=3