docs: @Nonnull
      public BugInstance addCalledMethod(ConstantPoolGen cpg, InvokeInstruction inv) {
          String className = inv.getClassName(cpg);
          String methodName = inv.getMethodName(cpg);
          String methodSig = inv.getSignature(cpg);
          addMethod(className, methodName, methodSig, inv.getOpcode() == Const.INVOKESTATIC);
          describe(MethodAnnotation.METHOD_CALLED);
          return this;
      }