code: public ValueType getArgument(InvokeInstruction ins, ConstantPoolGen cpg, int i, SignatureParser sigParser)
              throws DataflowAnalysisException {
          if (i >= sigParser.getNumParameters()) {
              throw new IllegalArgumentException("requesting parameter # " + i + " of " + sigParser);
          }
          return getStackValue(sigParser.getSlotsFromTopOfStackForParameter(i));
      }
docs: Get the <i>i</i>th argument passed to given method invocation.
  
  @param ins
  the method invocation instruction
  @param cpg
  the ConstantPoolGen for the class containing the method
  @param i
  index of the argument; 0 for the first argument, etc.
  @return the <i>i</i>th argument
  @throws DataflowAnalysisException