dataType property
Things like URL, Email, Currency, Timestamp (rather than string, int64...) Possible string values are:
- "DATA_TYPE_UNSPECIFIED"
 - "EMAIL"
 - "URL"
 - "CURRENCY"
 - "TIMESTAMP"
 - "DOMAIN_NAME" : Domain is a web url string with one top-level private domain and a suffix (for example: google.com, walmart.com)
 
Implementation
core.String? dataType;