protected void internalLoad() {
        val t0 = System.currentTimeMillis();
        try {
            this.loaded = initializeMetadataResolver();
        } finally {
            val t1 = System.currentTimeMillis();
            LOGGER.debug("Metadata resolution took: {} ms", t1 - t0);
        }

    }
Resolve and download idp metadata to form a metadata resolver.
<p>
The resolver supports proxies using {@link Proxy} when fetching metadata over URL resources.

@author Misagh Moayyed
@since 1.7
pac4j-saml/src/main/java/org/pac4j/saml/metadata/SAML2IdentityProviderMetadataResolver.java