code: def diff(s: "Stream[float]", periods: int = 1) -> "Stream[float]":
      """Computes the difference of a float stream.
  
      Parameters
      ----------
      s : `Stream[float]`
          A float stream.
      periods : int, default 1
          The number of periods to lag for until computing the difference.
  
      Returns
      -------
      `Stream[float]`
          The difference stream of `s`.
      """
      return BinOp(np.subtract)(s, s.lag(periods)).astype("float")
  
file_path: tensortrade/tensortrade/feed/api/float/utils.py
imports: import numpy
  from tensortrade.feed.core.base import Stream
  from tensortrade.feed.core.operators import BinOp
  from tensortrade.feed.api.float import Float
label_desc: Use image node_id 7 for calling a global function with example usage: diff(s, periods) and returns: BinOp