question: public void simulateMethod ( SootMethod method , ReferenceVariable thisVar , ReferenceVariable returnVar , ReferenceVariable params [ ] ) { String subSignature = method . getSubSignature ( ) ; if ( subSignature . equals ( "java.lang.Object doPrivileged(java.security.PrivilegedAction)" ) ) { java_security_AccessController_doPrivileged ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.lang.Object doPrivileged(java.security.PrivilegedExceptionAction)" ) ) { java_security_AccessController_doPrivileged ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.lang.Object doPrivileged(java.security.PrivilegedAction,java.security.AccessControlContext)" ) ) { java_security_AccessController_doPrivileged ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.lang.Object doPrivileged(java.security.PrivilegedExceptionAction,java.security.AccessControlContext)" ) ) { java_security_AccessController_doPrivileged ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.security.AccessControlContext getStackAccessControlContext()" ) ) { java_security_AccessController_getStackAccessControlContext ( method , thisVar , returnVar , params ) ; return ; } else if ( subSignature . equals ( "java.security.AccessControlContext getInheritedAccessControlContext()" ) ) { java_security_AccessController_getInheritedAccessControlContext ( 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.