code: def find_wells_without_curve(self, mnemonic, alias=None):
          
          return Project([w for w in self if w.get_curve(mnemonic, alias=alias) is None])
docs: Returns a new Project with only the wells which DO NOT have the named curve.
  
          Args:
              menmonic (str): the name of the curve to look for.
              alias (dict): a welly alias dictionary.
          
          Returns:
              project.