'Retrieve the value for a given key.
:param string key: The key of the parameter value to retrieve.
:param string default: default value if parameter is missing.
:return: The value of the parameter, or ``default`` if it does not exist.
:rtype: string'

@api.model
def get_param(self, key, default=False):

    return (self._get_param(key) or default)
