class_docstr: Metric base class.
docstr: :return: Formated string representation of the metric.
code: def __repr__(self):
      """:return: Formated string representation of the metric."""
  
file_path: MatchZoo/matchzoo/engine/base_metric.py
imports: import abc
  import numpy
label_desc: Use image node_id 2 for calling the BaseMetric obj's underlying member method code with example usage: obj.__repr__() without return types