question: public void simulateMethod ( SootMethod method , ReferenceVariable thisVar , ReferenceVariable returnVar , ReferenceVariable params [ ] ) { String subSignature = method . getSubSignature ( ) ; if ( subSignature . equals ( "void arraycopy(java.lang.Object,int,java.lang.Object,int,int)" ) ) { java_lang_System_arraycopy ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "void setIn0(java.io.InputStream)" ) ) { java_lang_System_setIn0 ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "void setOut0(java.io.PrintStream)" ) ) { java_lang_System_setOut0 ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "void setErr0(java.io.PrintStream)" ) ) { java_lang_System_setErr0 ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.util.Properties initProperties(java.util.Properties)" ) ) { java_lang_System_initProperties ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.lang.String mapLibraryName(java.lang.String)" ) ) { java_lang_System_mapLibraryName ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.lang.Class getCallerClass()" ) ) { java_lang_System_getCallerClass ( method , thisVar , returnVar , params ) ; return ; } else { defaultMethod ( method , thisVar , returnVar , params ) ; return ; } }
target:  Implements the abstract method simulateMethod. It distributes the request to the corresponding methods  by signatures.