code: public String[] getInputsForFunction(DifferentialFunction function) {
          if (!ops.containsKey(function.getOwnName()))
              throw new ND4JIllegalStateException("Illegal function instance id found " + function.getOwnName());
          List<String> inputs = ops.get(function.getOwnName()).getInputsToOp();
          return inputs == null ? null : inputs.toArray(new String[inputs.size()]);
      }
docs: Returns the name(s) of the inputs for the given function
  
  @param function the function to get the inputs for
  @return the input ids for a given function