'Splits the ``string`` using ``separator`` as a delimiter string.
If a ``separator`` is not given, any whitespace string is a
separator. In that case also possible consecutive whitespace
as well as leading and trailing whitespace is ignored.
Split words are returned as a list. If the optional
``max_split`` is given, at most ``max_split`` splits are done, and
the returned list will have maximum ``max_split + 1`` elements.
Examples:
| @{words} =         | Split String | ${string} |
| @{words} =         | Split String | ${string} | ,${SPACE} |
| ${pre} | ${post} = | Split String | ${string} | ::    | 1 |
See `Split String From Right` if you want to start splitting
from right, and `Fetch From Left` and `Fetch From Right` if
you only want to get first/last part of the string.'

def split_string(self, string, separator=None, max_split=(-1)):

    if (separator == ''):
        separator = None
    max_split = self._convert_to_integer(max_split, 'max_split')
    return string.split(separator, max_split)
