https://github.com/spring-projects/spring-framework: Spring Core (Spring IO)
  • Juergen Hoeller 
Provides basic classes for exception handling and version detection,
and other core helpers that are not specific to any part of the framework.

/**
 * Provides basic classes for exception handling and version detection,
 * and other core helpers that are not specific to any part of the framework.
 */
@NonNullApi
@NonNullFields
package org.springframework.core;

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