def can_hold_child?(storable)
      Specimen === storable and storable.specimen_class == specimen_class and specimen_types.include?(storable.specimen_type)
    end
def can_hold_child?(storable)
      Specimen === storable and storable.specimen_class == specimen_class and specimen_types.include?(storable.specimen_type)
    end
Returns true if Storable is a Specimen and supported by this SpecimenArrayType.