Here is the (partial) API for this function. It will be called convert_to_Caesar(). It will take one argument: a string of text. It will return: a string of text. The letters in the argument will be processed as follows:

• uppercase letters will be left untouched
• lowercase letters will be converted to uppercase letters: 'a''A', 'b' 'B' etc.
• the full stop '.' will be translated to the letter 'X' (as 'X' is rare, we can use it to separate sentences)
• all other letters in the argument will be discarded

Put this in a python code