hSet abstract method
Sets field in the hash stored at key to value.
Returns 1 if field is a new field and was set,
or 0 if field already existed and was updated.
Throws a TRServerException if the key holds a non-hash value.
Adds a field-value pair to the hash stored at key. Returns the number of fields that were added. Usage:
await hSet('user:2', {'name':'john', 'age':'20'});
await hSet('user:2', {'name':'john'});
Implementation
Future<int> hSet(String key, Map<String, String> data);