private TaintMethodSummary getMethodSummary(InvokeInstruction obj) {
   String methodNameWithSig = obj.getMethodName(cpg) + obj.getSignature(cpg);
   String fullMethodName = getSlashedClassName(obj) + "." + methodNameWithSig;
   TaintMethodSummary methodSummary = methodSummaries.get(fullMethodName);
   if (methodSummary == null && TO_STRING_METHOD.equals(methodNameWithSig)) {
     methodSummary = TaintMethodSummary.getDefaultToStringSummary();
   }
   return methodSummary;
 }