TextBuffer.placeCursor

This function moves the “insert” and “selection_bound” marks simultaneously. If you move them to the same place in two steps with [gtk.text_buffer.TextBuffer.moveMark], you will temporarily select a region in between their old and new locations, which can be pretty inefficient since the temporarily-selected region will force stuff to be recalculated. This function moves them as a unit, which can be optimized.