class_docstr: Tensorforce error
class_docstr_tok: ["Tensorforce","error"]
code: def exists(name, value):
      return TensorforceError(
          message="{name} already exists: {value}.".format(
              name=name, value=value
          )
      )
  
file_path: tensorforce/tensorforce/exception.py
label_desc: Use image node_id 5 for calling the TensorforceError obj's underlying member method code with example usage: obj.exists(name, value) and returns: TensorforceError