code: def fillna(
      s: "Stream[float]", fill_value: float = 0.0
  ) -> "Stream[float]":
      """Fill in missing values with a fill value.
  
      Parameters
      ----------
      s : `Stream[float]`
          A float stream.
      fill_value : float
          A value to fill in missing values with.
  
      Returns
      -------
      `Stream[float]`
          An imputed stream via padding.
      """
      return FillNa(fill_value=fill_value)(s).astype("float")
  
imports: from tensortrade.feed.api.generic.imputation import FillNa, ForwardFill
  from tensortrade.feed.core.base import Stream
  from tensortrade.feed.api.float import Float
label_desc: Use image node_id 1 for calling a global function with example usage: fillna(s, fill_value) and returns: FillNa