code: public ClassicAuthenticator cluster(String adminName, String adminPassword) {
          this.clusterManagementCredential = new Credential(adminName, adminPassword);
          return this;
      }
docs: Sets the {@link CredentialContext#CLUSTER_MANAGEMENT} credential. Specific is ignored in this context.
  
  @param adminName the administrative login to use.
  @param adminPassword the administrative password to use.
  @return this {@link ClassicAuthenticator} for chaining.