code: def test_placholder():
      s = Stream.placeholder(dtype="float")
  
      s.push(5)
  
      assert s.value == 5
  
file_path: tensortrade/tests/tensortrade/unit/feed/core/test_base.py
imports: from tensortrade.feed.core import Stream, NameSpace
  from tensortrade.feed.core.base import Placeholder
label_desc: Use image node_id 4 for calling a global function with example usage: test_placholder() without return types