code: public boolean merge(ResourceMetadata other) {
          boolean modified = m_metrics.addAll(other.m_metrics);
          if (!modified) {
              modified = !m_attributes.equals(other.m_attributes);
          }
          m_attributes.putAll(other.m_attributes);
          return modified;
      }
docs: Merges the metrics and attributes from the given instance, to the current instance.
  
  @param other a {@link ResourceMetadata} object
  @return true if the meta-data was modified as a result of the merge, false otherwise