docstr: Gets the representation of the metric object with overridden parameters.
  Implemented in child classes.
  
  Returns
  ----------
  metric_string: str representing the metric object.
docstr_tok: ["Gets","the","representation","of","the","metric","object","with","overridden","parameters",".","Implemented","in","child","classes",".","Returns","--","--","--","--","--","metric_string",":","str","representing","the","metric","object","."]
code: def __str__(self):
      """
      Gets the representation of the metric object with overridden parameters.
      Implemented in child classes.
  
      Returns
      ----------
      metric_string: str representing the metric object.
      """
      raise NotImplementedError(
          "Should be overridden by the child class."
      )
  
imports: from functools import partial
  import numpy
  from .None import _catboost
label_desc: Use image node_id 2 for calling the BuiltinMetric obj's underlying member method code with example usage: obj.__str__() without return types