pattern_count: This validator builds a pattern mask for each value in a field. Alphanumeric characters are masked, while retaining other special characters. For example, 867-5309 will be masked to ddd-dddd, and f32-sk-39d would mask to add-aa-dda where a represents any A-Za-z character. Much like the previous validator, if the cardinality of learned patterns is less than or equal to the settings, patterns will be enforced during data generation. If the unique pattern count is above the settings, enforcement will be ignored.