public virtual char ToUpper(char c)
 {
     if (TextInfo.IsAscii(c) && this.IsAsciiCasingSameAsInvariant)
     {
         return(TextInfo.ToUpperAsciiInvariant(c));
     }
     return(TextInfo.InternalChangeCaseChar(this.m_dataHandle, this.m_handleOrigin, this.m_textInfoName, c, true));
 }