'Return my first existing child with a name in C{paths}.
C{paths} is expected to be a list of *pre-secured* path fragments;
in most cases this will be specified by a system administrator and not
an arbitrary user.
If no appropriately-named children exist, this will return L{None}.
@return: L{None} or the child path.
@rtype: L{None} or L{FilePath}'

def childSearchPreauth(self, *paths):

    for child in paths:
        p = self._getPathAsSameTypeAs(child)
        jp = joinpath(p, child)
        if exists(jp):
            return self.clonePath(jp)
