class_docstr: A data feed for working with live data in an online manner.
  
  All sources of data to be used with this feed must be a `Placeholder`. This
  ensures that the user can wait until all of their data has been loaded for the
  next time step.
  
  Parameters
  ----------
  streams : `List[Stream]`
      A list of streams to be used in the data feed.
class_docstr_tok: ["A","data","feed","for","working","with","live","data","in","an","online","manner",".","All","sources","of","data","to","be","used","with","this","feed","must","be","a","`","Placeholder","`",".","This","ensures","that","the","user","can","wait","until","all","of","their","data","has","been","loaded","for","the","next","time","step",".","Parameters","--","--","--","--","--","streams",":","`","List","[","Stream","]","`","A","list","of","streams","to","be","used","in","the","data","feed","."]
code: def __init__(self, streams: "List[Stream]"):
      super().__init__(streams)
  
      self.compile()
  
      edges = self.gather()
      src = set([s for s, t in edges])
      tgt = set([t for s, t in edges])
  
      self.start = [
          s for s in src.difference(tgt) if isinstance(s, Placeholder)
      ]
  
file_path: tensortrade/tensortrade/feed/core/feed.py
imports: from typing import List
  from tensortrade.feed.core.base import Stream, T, Placeholder, IterableStream
label_desc: Use image node_id 1 to create a new PushFeed object from inherited base classes: DataFeed with example: obj = PushFeed(streams)