https://access.redhat.com/webassets/avalon/d/red_hat_jboss_enterprise_application_platform/7.3/javadocs/javax/faces/el/VariableResolver.html
VariableResolver (Red Hat JBoss Enterprise Application Platform 7.3.0.GA public API)
red hat jboss
https://jakarta.ee/specifications/platform/8/apidocs/javax/faces/el/variableresolver
VariableResolver (Jakarta EE 8 Specification APIs)
jakarta eespecificationapis