Initializes @iter with the “end iterator,” one past the last valid
character in the text buffer.
If dereferenced with [method@Gtk.TextIter.get_char], the end
iterator has a character value of 0.
The entire buffer lies in the range from the first position in
the buffer (call [method@Gtk.TextBuffer.get_start_iter] to get
character position 0) to the end iterator.
Initializes @iter with the “end iterator,” one past the last valid character in the text buffer.
If dereferenced with [method@Gtk.TextIter.get_char], the end iterator has a character value of 0. The entire buffer lies in the range from the first position in the buffer (call [method@Gtk.TextBuffer.get_start_iter] to get character position 0) to the end iterator.