Sets the specified field in the hash stored at key to value. If the key does not exist, a new key holding a hash is created. If field already exists in the hash, it is overwritten.
|key||string||key holding the hash to set the field of.|
|field||string||field to set in the hash.|
|value||string||value to set the field to.|
|Type||Resolves with||Rejected when|
|Promise<number>||On success, the promise resolves with the number of fields that were added.||If the hash does not exist, the promise is rejected with an error.|