def savable_prerequisite?
      return true if cascaded? and @flags.include?(:no_cascade_update_to_create)
      return false unless independent? and saved?
      return true unless collection?
      inv_prop = inverse_property
      inv_prop.nil? or inv_prop.collection?
    end
def savable_prerequisite?
      return true if cascaded? and @flags.include?(:no_cascade_update_to_create)
      return false unless independent? and saved?
      return true unless collection?
      inv_prop = inverse_property
      inv_prop.nil? or inv_prop.collection?
    end
Returns whether this attribute's referents must exist before an instance of the
 declarer class can be created. An attribute is a savable prerequisite if it is
 either:
 * a {#cascaded?} dependent which does not #{#cascade_update_to_create?}, or
 * a {#saved?} {#independent?} 1:M or M:N association.

 @return [Boolean] whether this attribute is a create prerequisite