https://github.com/spring-projects/spring-framework: Spring Core (Spring IO)
  • Juergen Hoeller 
Core support package for annotations, meta-annotations, and composed
annotations with attribute overrides.

/**
 * Core support package for annotations, meta-annotations, and composed
 * annotations with attribute overrides.
 */
@NonNullApi
@NonNullFields
package org.springframework.core.annotation;

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