class_docstr: An object with some value that can be observed.
  
  An object to which a `listener` can be attached to and be alerted about on
  an event happening.
  
  Attributes
  ----------
  listeners : list of listeners
      A list of listeners that the object will alert on events occurring.
  
  Methods
  -------
  attach(listener)
      Adds a listener to receive alerts.
  detach(listener)
      Removes a listener from receiving alerts.
class_docstr_tok: ["An","object","with","some","value","that","can","be","observed",".","An","object","to","which","a","`","listener","`","can","be","attached","to","and","be","alerted","about","on","an","event","happening",".","Attributes","--","--","--","--","--","listeners",":","list","of","listeners","A","list","of","listeners","that","the","object","will","alert","on","events","occurring",".","Methods","--","--","--","-","attach","(","listener",")","Adds","a","listener","to","receive","alerts",".","detach","(","listener",")","Removes","a","listener","from","receiving","alerts","."]
code: def __init__(self):
      self.listeners = []
  
file_path: tensortrade/tensortrade/core/base.py
imports: import uuid
  from abc import ABCMeta
  from tensortrade.core.clock import Clock
label_desc: Use image node_id 1 to create a new Observable object  with example: obj = Observable()