How to use the pandasticsearch.operators.AndFilter function in pandasticsearch

def __and__(self, x):
        # Combine results
        if isinstance(self, AndFilter):
            self.subtree['must'].append(x.subtree)
            return self
        elif isinstance(x, AndFilter):
            x.subtree['must'].append(self.subtree)
            return x
        return AndFilter(self, x)

def __and__(self, x):
        # Combine results
        if isinstance(self, AndFilter):
            self.subtree['must'].append(x.subtree)
            return self
        elif isinstance(x, AndFilter):
            x.subtree['must'].append(self.subtree)
            return x
        return AndFilter(self, x)

def __and__(self, x):
        # Combine results
        if isinstance(self, AndFilter):
            self.subtree['must'].append(x.subtree)
            return self
        elif isinstance(x, AndFilter):
            x.subtree['must'].append(self.subtree)
            return x
        return AndFilter(self, x)

def __init__(self, *args):
        [isinstance(x, BooleanFilter) for x in args]
        super(AndFilter, self).__init__()
        self._filter = {'bool': {'must': [x.build() for x in args]}}