function getBlockNodes(nodes) {
  // TODO(perf): update `nodes` instead of creating a new object?
  var node = nodes[0];
  var endNode = nodes[nodes.length - 1];
  var blockNodes;

  for (var i = 1; node !== endNode && (node = node.nextSibling); i++) {
    if (blockNodes || nodes[i] !== node) {
      if (!blockNodes) {
        blockNodes = jqLite(slice.call(nodes, 0, i));
      }
      blockNodes.push(node);
    }
  }

  return blockNodes || nodes;
}
Return the DOM siblings between the first and last node in the given array.
@param {Array} array like object
@returns {Array} the inputted object or a jqLite collection containing the nodes