code: public CollectionRequest<CustomField> findByWorkspace(String workspace) {
      
          String path = String.format("/workspaces/%s/custom_fields", workspace);
          return new CollectionRequest<CustomField>(this, CustomField.class, path, "GET");
      }
docs: Returns a list of the compact representation of all of the custom fields in a workspace.
  
  @param  workspace The workspace or organization to find custom field definitions in.
  @return Request object