Method get_single_valid_child_data

arrow-data/src/data.rs:1246–1252

Ensures that this array data has a single child_data with the expected type, and calls `validate()` on it. Returns a reference to that child_data

(
        &self,
        expected_type: &DataType,
    )

    /// expected type, and calls `validate()` on it. Returns a
    /// reference to that child_data
    fn get_single_valid_child_data(
        &self,
        expected_type: &DataType,
    ) -> Result<&ArrayData, ArrowError> {
        self.validate_num_child_data(1)?;
        self.get_valid_child_data(0, expected_type)
    }

    /// Returns `Err` if self.child_data does not have exactly `expected_len` elements
    fn validate_num_child_data(&self, expected_len: usize) -> Result<(), ArrowError> {