Appends the specified segment of "string" to the RTF data.
Copy from <code>start</code> up to, but excluding, <code>end</code>.
@param string string to copy a segment from. Must not contain
line breaks. Line breaks should be written using writeLineDelimiter()
@param start start offset of segment. 0 based.
@param end end offset of segment
Appends the specified segment of "string" to the RTF data. Copy from <code>start</code> up to, but excluding, <code>end</code>.
@param string string to copy a segment from. Must not contain line breaks. Line breaks should be written using writeLineDelimiter() @param start start offset of segment. 0 based. @param end end offset of segment