class_docstr: An operator stream that accumulates values of a given stream.
  
  Parameters
  ----------
  func : Callable[[T,T], T]
      An accumulator function.
  dtype : str
      The data type of accumulated value.
class_docstr_tok: ["An","operator","stream","that","accumulates","values","of","a","given","stream",".","Parameters","--","--","--","--","--","func",":","Callable","[","[","T",",","T","]",",","T","]","An","accumulator","function",".","dtype",":","str","The","data","type","of","accumulated","value","."]
code: def __init__(
      self, func: "Callable[[T, T], T]", dtype: str = None
  ) -> None:
      super().__init__(dtype)
      self.func = func
      self.past = None
  
imports: from typing import Callable, TypeVar
  import numpy
  from tensortrade.feed.core.base import Stream, T
label_desc: Use image node_id 1 to create a new Accumulator object from inherited base classes: Stream with example: obj = Accumulator(func, dtype)