code: def detect_parent_image_nvr(self, image_name, inspect_data=None):
          
  
          if inspect_data is None:
              inspect_data = self.workflow.builder.parent_image_inspect(image_name)
          labels = Labels(inspect_data[INSPECT_CONFIG].get('Labels', {}))
  
          label_names = [Labels.LABEL_TYPE_COMPONENT, Labels.LABEL_TYPE_VERSION,
                         Labels.LABEL_TYPE_RELEASE]
          label_values = []
  
          for lbl_name in label_names:
              try:
                  _, lbl_value = labels.get_name_and_value(lbl_name)
                  label_values.append(lbl_value)
              except KeyError:
                  self.log.info("Failed to find label '%s' in parent image '%s'.",
                                labels.get_name(lbl_name), image_name)
  
          if len(label_values) != len(label_names):  # don't have all the necessary labels
              self.log.info("Image '%s' NVR missing; not searching for Koji build.", image_name)
              return None
  
          return '-'.join(label_values)
docs: Look for the NVR labels, if any, in the image.
  
          :return NVR string if labels found, otherwise None