question: private static boolean filter ( StackTraceElement e ) { if ( e . getLineNumber ( ) == 1 ) { return false ; } String cn = e . getClassName ( ) ; if ( cn . contains ( "java.lang.Thread" ) ) { return false ; } if ( cn . contains ( "junit.runner" ) || cn . contains ( "org.junit.internal" ) || cn . contains ( "junit4.runner" ) ) { return false ; } if ( cn . contains ( "java.lang.reflect" ) || cn . contains ( "sun.reflect" ) ) { return false ; } if ( cn . contains ( ".RxJavaAssemblyException" ) ) { return false ; } if ( cn . contains ( "OnAssembly" ) || cn . contains ( "RxJavaAssemblyTracking" ) || cn . contains ( "RxJavaPlugins" ) ) { return false ; } return true ; }
target:  Filters out irrelevant stacktrace entries.