An AI has infected a text with a character!!
This text is now fully mutated to this character.
If the text or the character are empty, return an empty string. There will never be a case when both are empty as nothing is going on!!
Note: The character is a string of length 1 or an empty string.
text before = "abc"
character = "z"
text after = "zzz"
def contamination(text, char)
char * text.size
end