title: How to use existing libraries made by google?
body: <p>I want to import <strong>libcore</strong> package which is not present by default in android studio 2.3.3. <strong>compile 'org.robovm:robovm-rt:+'</strong> in <strong>build.gradle</strong> does not work, it gives <em>Failed to resolve</em> error. Is there any other option besides downloading its jar. </p>
  
  <p>I want to use InflatorInputStream.java file in my app with some modification in it. I want to get total bytes read in inputstream (not outputstream which is returned by in.read())</p>
  
  <p>In build.gradle</p>
  
  <pre><code>dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      compile group: 'org.robolectric', name: 'android-libcore', version: '4.3_r2.robolectric-0'
      androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
          exclude group: 'com.android.support', module: 'support-annotations'
      })
      compile 'com.android.support:appcompat-v7:26.+'
      compile 'com.android.support.constraint:constraint-layout:1.0.2'
      testCompile 'junit:junit:4.12'
  }
  </code></pre>
  
  <p>In Messages tab:</p>
  
  <pre><code>Information:Gradle tasks [:app:assembleDebug]
  C:\Users\pebble\AndroidStudioProjects\Test\app\src\main\java\pebble\test\InflaterInputStream.java
  Error:(28, 26) error: package libcore.io does not exist
  Error:(107, 34) error: cannot find symbol class RAFStream
  Error:(139, 15) error: cannot find symbol method checkOffsetAndCount(int,int,int)
  Error:(167, 22) error: cannot find symbol class DataFormatException
  Error:(186, 20) error: cannot find symbol class RAFStream
  Error:(186, 44) error: cannot find symbol class RAFStream
  Error:(187, 26) error: illegal start of type
  Error:(213, 16) error: cannot find symbol variable Streams
  Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
  &gt; Compilation failed; see the compiler error output for details.
  Information:BUILD FAILED
  Information:Total time: 52.353 secs
  Information:9 errors
  Information:0 warnings
  Information:See complete output in console
  </code></pre>