@Override
    public boolean supports(final WebContext context) {
        val grantType = configurationContext.getObject().getRequestParameterResolver().resolveRequestParameter(context, OAuth20Constants.GRANT_TYPE);
        return OAuth20Utils.isGrantType(grantType.map(String::valueOf).orElse(StringUtils.EMPTY), getGrantType());
    }
This is {@link BaseOAuth20TokenRequestValidator}.

@author Misagh Moayyed
@since 5.3.0
support/cas-server-support-oauth-core-api/src/main/java/org/apereo/cas/support/oauth/validator/token/BaseOAuth20TokenRequestValidator.java