code: public ManualGrpcSecurityMetadataSource remove(final ServiceDescriptor service) {
          requireNonNull(service, "service");
          for (final MethodDescriptor<?, ?> method : service.getMethods()) {
              this.accessMap.remove(method);
          }
          return this;
      }
docs: Removes all access predicates for the all methods of the given service. After that, the default will be used for
  those methods.
  
  @param service The service to protect with only the default.
  @return This instance for chaining.
  @see #setDefault(AccessPredicate)