@classmethod
def check_caom2_element(cls, caom2_element):
    """
        Checks that an element is a valid caom2_element in the blueprint. It
        checks that it's part of the ObsBlueprint._CAOM2_ELEMENTS
        :param caom2_element: name CAOM2 element to check
        :raises KeyError
        """
    if caom2_element not in cls._CAOM2_ELEMENTS:
        raise KeyError('{} not a valid CAOM2 element name (mispelling?).'.
            format(caom2_element))
