code: function _getAdjacentBlankNodeName(node, id) {
    return (node.type === 'blank node' && node.value !== id ? node.value : null);
  }
docs: A helper function that gets the blank node name from an RDF quad node
  (subject or object). If the node is a blank node and its value
  does not match the given blank node ID, it will be returned.
  
  @param node the RDF quad node.
  @param id the ID of the blank node to look next to.
  
  @return the adjacent blank node name or null if none was found.