<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def find(self, *strings, **kwargs):
 """ Search the entire editor for lines that match the string. .. code-block:: Python string = '''word one word two three''' ed = Editor(string) ed.find('word') # [(0, "word one"), (1, "word two")] Args: strings (str):
 Any number of strings to search for keys_only (bool):
 Only return keys start (int):
 Optional line to start searching on stop (int):
 Optional line to stop searching on Returns: results: If multiple strings searched a dictionary of string key, (line number, line) values (else just values) """

        start = kwargs.pop("start", 0)
        stop = kwargs.pop("stop", None)
        keys_only = kwargs.pop("keys_only", False)
        results = {string: [] for string in strings}
        stop = len(self) if stop is None else stop
        for i, line in enumerate(self[start:stop]):
            for string in strings:
                if string in line:
                    if keys_only:
                        results[string].append(i)
                    else:
                        results[string].append((i, line))
        if len(strings) == 1:
            return results[strings[0]]
        return results