Deletes a substring from the MutableBuffer that starts at the nth word and is of length whitespace-delimited words. If you omit length, or if length is greater than the number of words from n to the end of the receiving buffer, the method deletes the remaining words in the receiving buffer (including the nth word). The length must be a positive whole number or zero. The n must be a positive whole number. If n is greater than the number of words in the receiving buffer, the method returns the receiving buffer unchanged. The portion deleted includes any whitespace characters following the final word involved but none of the whitespace characters preceding the first word involved.