private boolean isAliasRequested(String clusterName, String canonicalizedAlias) {
    return (clusterName == null) || canonicalizedAlias.toLowerCase().startsWith(createAliasPrefix(clusterName));
  }
Tests the canonicalized alias name to see if it should be returned within the set of credentials.
<p/>
This filters out all credentials not tagged for a specific cluster.

@param clusterName        the name of the cluster
@param canonicalizedAlias the canonicalized alias
@return true if the alias is tagged for the requested cluster; otherwise false
ambari-server/src/main/java/org/apache/ambari/server/security/encryption/CredentialStoreServiceImpl.java