code: function anchorFirst() {
      self.startRow = anchorRow;
      self.startNode = selection.anchorNode;
      self.startOffset = selection.anchorOffset;
      self.endRow = focusRow;
      self.endNode = selection.focusNode;
      self.endOffset = selection.focusOffset;
    }
docs: The dom selection object has no way to tell which nodes come first in the document, so we have to figure that out.  This function is used when we detect that the "anchor" node is first.