Fixed missing guava dependecies which where previously build into espresso-core.aar

Author: slinzner

testrunner/AndroidJunitRunnerSample/app/build.gradle

@@ -29,6 +29,7 @@ android {
 dependencies {
     // App's dependencies, including test
     compile 'com.android.support:support-annotations:21.0.3'
+    compile 'com.google.guava:guava:18.0'
 
     // Testing-only dependencies
     androidTestCompile 'com.android.support.test:testing-support-lib:0.1'

testrunner/AndroidJunitRunnerSample/app/src/main/java/com/example/android/testing/androidjunitrunnersample/Calculator.java

@@ -16,6 +16,8 @@
 
 package com.example.android.testing.androidjunitrunnersample;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
 /**
  * A simple calculator with a basic set of operations.
  */
@@ -41,9 +43,7 @@ public double sub(double firstOperand, double secondOperand) {
      * Divide operation
      */
     public double div(double firstOperand, double secondOperand) {
-        if (secondOperand == 0) {
-            throw new IllegalArgumentException("secondOperand must be != 0, you cannot divide by zero");
-        }
+        checkArgument(secondOperand != 0, "secondOperand must be != 0, you cannot divide by zero");
         return firstOperand / secondOperand;
     }