Group a range of text fragments into a set of lines.
Calling Select will return a list of TextFragments corresponding
to the section of text you are interested in. However each
TextFragment may only make up a small portion of a word. Calling
this function allows you to group connected fragments into
continuous sections with a common rectangular area.
Strictly speaking this grouping does not always correspond to
lines. For example two fragments on the same line, separated by a
large distance, will not be considered contiguous. However for most
purposes the two broadly correspond.