NodeContext represents a position in the document + layout-related
information attached to it. When after=false and offsetInNode=0, the
position is inside the element (node), but just before its first child.
When offsetInNode>0 it represents offset in the textual content of the
node. When after=true it represents position right after the last child
of the node. boxOffset is incremented by 1 for any valid node position.
NodeContext represents a position in the document + layout-related information attached to it. When after=false and offsetInNode=0, the position is inside the element (node), but just before its first child. When offsetInNode>0 it represents offset in the textual content of the node. When after=true it represents position right after the last child of the node. boxOffset is incremented by 1 for any valid node position.