class_docstr: stores a single scalar value and its gradient 
class_docstr_tok: ["stores","a","single","scalar","value","and","its","gradient"]
code: def __neg__(self):  # -self
      return self * -1
  
file_path: micrograd/micrograd/engine.py
label_desc: Use image node_id 7 for calling the Value obj's underlying member method code with example usage: obj.__neg__() and returns: unknown