Resolve an expression
        Args:
            body, ExpressionOperation: The JSON encoded expression to be evaluated (required)
            sparsity, float: Sparsify the resulting expression to this percentage (optional)
        Returns:
            Fingerprint
        Raises:
            CorticalioException: if the request was not successful

def getFingerprintForExpression(self, body, sparsity=1.0):
        """Resolve an expression
        Args:
            body, ExpressionOperation: The JSON encoded expression to be evaluated (required)
            sparsity, float: Sparsify the resulting expression to this percentage (optional)
        Returns:
            Fingerprint
        Raises:
            CorticalioException: if the request was not successful
        """
        return self._expressions.resolveExpression(self._retina, body, sparsity)