class_docstr: On-balance volume (OBV)
  
  It relates price and volume in the stock market. OBV is based on a
  cumulative total volume.
  
  https://en.wikipedia.org/wiki/On-balance_volume
  
  Args:
      close(pandas.Series): dataset 'Close' column.
      volume(pandas.Series): dataset 'Volume' column.
      fillna(bool): if True, fill nan values.
code: def __init__(
      self, close: pd.Series, volume: pd.Series, fillna: bool = False
  ):
      self._close = close
      self._volume = volume
      self._fillna = fillna
      self._run()
  
imports: import typing
  import numpy
  import pandas
  from ta.utils import IndicatorMixin, _ema
label_desc: Use image node_id 1 to create a new OnBalanceVolumeIndicator object from inherited base classes: IndicatorMixin with example: obj = OnBalanceVolumeIndicator(close, volume, fillna)