def Between(field, from_value, to_value):
    """
    A criterion used to search for records having `field`'s value included in a range defined by `from_value` and `to_value`. 
    This is an idea criterion to seahrch using date conditions. For example
    
    * search for cases created between two dates
    * search for alerts with cvss custom field greater that 2 and lesser than 9

    Arguments:
        field (str): field name
        from_value (Number): Lower limit of the range
        to_value (Number): Higher limit of the range

    Returns:
        dict: JSON repsentation of the criterion
            ```python
            # Query to search for alerts with cvss custom field greater that 2 and lesser than 9
            query = Between('customFields.cvss.float', 2, 9)
            ```
            produces
            ```json
            {
                "_between": {
                    "_field": "customFields.cvss.float",
                    "_from": 2,
                    "_to": 9
                }
            }
            ```
    """
    return {'_between': {'_field': field, '_from': from_value, '_to': to_value}}