code: public static boolean isRelationshipParsable(JsonNode dataNode) {
  		return dataNode != null && dataNode.hasNonNull(JSONAPISpecConstants.ID) && dataNode.hasNonNull(JSONAPISpecConstants.TYPE) &&
  				!dataNode.get(JSONAPISpecConstants.ID).isContainerNode() && !dataNode.get(JSONAPISpecConstants.TYPE).isContainerNode();
  	}
docs: Returns <code>true</code> in case 'DATA' note has 'ID' and 'TYPE' attributes.
  @param dataNode relationship data node
  @return <code>true</code> if node has required attributes, else <code>false</code>