// - the first one to preserve, valid range [0;initialCharToRemove-1] or the empty range if initialCharToRemove==0
// - the second one to remove, valid range [initialCharToRemove;endCharToRemove]
// - the third one to preserve, valid range [endCharToRemove+1;len-1] or the empty range if endCharToRemove==len-1
// - the first one to preserve, valid range [0;initialCharToRemove-1] or the empty range if initialCharToRemove==0
// - the second one to remove, valid range [initialCharToRemove;endCharToRemove]
// - the third one to preserve, valid range [endCharToRemove+1;len-1] or the empty range if endCharToRemove==len-1