class_docstr: F1 score 
docstr: compute metric 
docstr_tok: ["compute","metric"]
code: def call(self, y_true=None, y_pred=None, arguments=None):
      """compute metric"""
      average = arguments["average"].lower()
      return metrics.f1_score(y_true, y_pred, average=average)
  
imports: import os
  import abc
  from absl import logging
  import numpy
  from sklearn import metrics
  from seqeval.metrics import classification_report
  from delta.utils.register import registers
  from delta.utils.postprocess.postprocess_utils import ids_to_sentences
  from rouge import FilesRouge
  from sacrebleu import corpus_bleu
  from delta.utils.metrics import metric_utils
label_desc: Use image node_id 2 for calling the F1ScoreCal obj's underlying member method code with example usage: obj.call(y_true, y_pred, arguments) and returns: metrics