(self)
return bool(self.impl['is_valid'](self))
True if the geometry is valid (definition depends on sub-class),
        else False
True if the geometry is valid (definition depends on sub-class),
        else False
True if the geometry is valid ( definition depends on sub - class ) else False
def is_valid(self):
        """True if the geometry is valid (definition depends on sub-class),
        else False"""
        return bool(self.impl['is_valid'](self))
def is_valid ( self ) : return bool ( self . impl [ 'is_valid' ] ( self ) )