'Returns the child elements of the specified element as a list.
The element whose children to return is specified using ``source`` and
``xpath``. They have exactly the same semantics as with `Get Element`
keyword.
All the direct child elements of the specified element are returned.
If the element has no children, an empty list is returned.
Examples using ``${XML}`` structure from `Example`:
| ${children} =    | Get Child Elements | ${XML} |             |
| Length Should Be | ${children}        | 4      |             |
| ${children} =    | Get Child Elements | ${XML} | xpath=first |
| Should Be Empty  | ${children}        |        |             |'

def get_child_elements(self, source, xpath='.'):

    return list(self.get_element(source, xpath))
