https://github.com/spring-projects/spring-framework: Spring Object/Relational Mapping (Spring IO)
  • Juergen Hoeller 
Internal support for managing JPA persistence units.

/**
 * Internal support for managing JPA persistence units.
 */
@NonNullApi
@NonNullFields
package org.springframework.orm.jpa.persistenceunit;

import org.springframework.lang.NonNullApi;
import org.springframework.lang.NonNullFields;