Function cast 

pub fn cast<S: AsRef<str>>(
    map: &[(S, DataType)],
    data: &RecordBatch,
    allow_cast_fail: bool,
) -> Result<RecordBatch>

Casts columns according to given (column name, target data type) pairs.

Returns error if casting a row fails and allow_cast_fail is set to false. Writes null to output if casting a row fails and allow_cast_fail is set to true.