As a data model maintainer, I want to check that some Properties are only used on Lexemes with certain languages, in order to ensure that they are used correctly.
**Problem:**
@Esc3300 created a constraint Item [language required by this Lexeme](https://www.wikidata.org/wiki/Q55819106). Presumably, we should support it.
**Example:**
The constraint type is used on the property [Japanese pitch accent type](https://www.wikidata.org/wiki/Property:P5426), with the language [Japanese](https://www.wikidata.org/wiki/Q5287).
**Screenshots/mockups:**
Message drafts:
For the case where there is only one allowed language defined on the Property:
> The Property [Japanese pitch accent type](https://www.wikidata.org/wiki/Property:P5426) should only be used on Lexemes in [Japanese](https://www.wikidata.org/wiki/Q5287).
For the case where there are multiple allowed languages defined on the Property:
> This Property should only be used on Lexemes in one of the following languages:
> * [Japanese](https://www.wikidata.org/wiki/Q5287)
> * whatever
> * …
**BDD**
GIVEN I am visiting a lexeme using a property with a “language required by this lexeme” constraint on either the Lexeme-level statements or on its Forms or Senses
AND the lexeme does not have the required language
THEN there is a “constraint violation” icon on the statement(s) with that property
AND the violation message explains the problem, including listing the allowed language(s)
**Acceptance criteria:**
* the constraint type is implemented
* after editing the language and reloading the page, the violation is no longer shown
* for now it is not necessary to remove the constraint violation indicator without reloading the page
**Open questions:**
* If more than one language item is specified in the constraint parameters, this means “one of these languages”, correct? @Esc3300 @Ivan_A_Krestinin -> Yes!