/// <summary>
/// Moves the range the specified number of units in the text. Note that the text is not altered. Instead the
/// range spans a different part of the text.
/// If the range is degenerate, this method tries to move the insertion point count units. If the range is nondegenerate
/// and count is greater than zero, this method collapses the range at its end point, moves the resulting range forward
/// to a unit boundary (if it is not already at one), and then tries to move count - 1 units forward. If the range is
/// nondegenerate and count is less than zero, this method collapses the range at the starting point, moves the resulting
/// range backward to a unit boundary (if it isn't already at one), and then tries to move |count| - 1 units backward.
/// Thus, in both cases, collapsing a nondegenerate range, whether or not moving to the start or end of the unit following
/// the collapse, counts as a unit.
/// </summary>
/// <param name="unit">The textual unit for moving.</param>
/// <param name="count">The number of units to move. A positive count moves the range forward.
/// A negative count moves backward. A count of 0 has no effect.</param>
/// <returns>The number of units actually moved, which can be less than the number requested if
/// moving the range runs into the beginning or end of the document.</returns>
public int Move(TextUnit unit, int count)
{
ValidateUnitArgument(unit, "unit");
// note: we could optimize the case of count==0 and just return 0.
return(UiaCoreApi.TextRange_Move(_hTextRange, unit, count));
}