class_docstr: Load beat times from file or handle.
class_docstr_tok: ["Load","beat","times","from","file","or","handle","."]
docstr: Add beat loading related arguments to an existing parser.
  
  Parameters
  ----------
  parser : argparse parser instance
      Existing argparse parser object.
  beats : FileType, optional
      Where to read the beats from ('single' mode).
  beats_suffix : str, optional
      Suffix of beat files ('batch' mode)
  
  Returns
  -------
  argparse argument group
      Beat loading argument parser group.
code: def add_arguments(parser, beats=sys.stdin, beats_suffix=".beats.txt"):
      """
      Add beat loading related arguments to an existing parser.
  
      Parameters
      ----------
      parser : argparse parser instance
          Existing argparse parser object.
      beats : FileType, optional
          Where to read the beats from ('single' mode).
      beats_suffix : str, optional
          Suffix of beat files ('batch' mode)
  
      Returns
      -------
      argparse argument group
          Beat loading argument parser group.
  
      """
      import argparse
  
      # add beat loading options to the existing parser
      g = parser.add_argument_group("beat loading arguments")
      g.add_argument(
          "--beats",
          type=argparse.FileType("rb"),
          default=beats,
          help="where/how to read the beat positions from "
          "[default: single: STDIN]",
      )
      g.add_argument(
          "--beats_suffix",
          type=str,
          default=beats_suffix,
          help="file suffix of the beat files [default: "
          "%(default)s]",
      )
      # return the argument group so it can be modified if needed
      return g
  
imports: from __future__ import absolute_import, division, print_function
  import sys
  import warnings
  import numpy
  from .beats import threshold_activations
  from .beats_hmm import BarStateSpace, BarTransitionModel, GMMPatternTrackingObservationModel, MultiPatternStateSpace, MultiPatternTransitionModel, RNNBeatTrackingObservationModel, RNNDownBeatTrackingObservationModel
  from ..ml.hmm import HiddenMarkovModel
  from ..processors import ParallelProcessor, Processor, SequentialProcessor
  from ..utils import string_types
label_desc: Use image node_id 5 for calling the LoadBeatsProcessor obj's underlying member method code with example usage: obj.add_arguments(parser, beats, beats_suffix) and returns: g