def get_metadata(klass, fields={}, less=[])
      if @option.all
        # Don't remove keys specified in fields
        less += (Rudy::Metadata::COMMON_FIELDS - fields.keys)
      end
      klass.list(fields, less) || []
    end
def get_metadata(klass, fields={}, less=[])
      if @option.all
        # Don't remove keys specified in fields
        less += (Rudy::Metadata::COMMON_FIELDS - fields.keys)
      end
      klass.list(fields, less) || []
    end
* +klass+ a Rudy::Metadata class. e.g. Rudy::Machines

 This method takes two optional args for adding or
 removing metadata attributes to modify the select query.
 When all is specified we want to find disks in every env
 environment and role to we remove these attributes from
 the select.