The feature attributes. It is a JSON object that contains a dictionary of name-value pairs.
The names are the feature field names. The values are the field values and they can be any of the
standard JSON types - string, number and boolean. Note that date values are encoded as numbers.
The number represents the number of milliseconds since epoch (January 1, 1970) in UTC.
The Esri feature layer containing field metadata for formatting attribute data. Only necessary when
the feature is not associated with an Essentials Layer.
The primary key value for the feature. If specified, layer must also be specified.
In this case, the {@link webMap.Feature.attributes} and {@link webMap.Feature.geometry} should not be specified. Instead,
they will be fetched by querying the layer.
The feature attributes. It is a JSON object that contains a dictionary of name-value pairs. The names are the feature field names. The values are the field values and they can be any of the standard JSON types - string, number and boolean. Note that date values are encoded as numbers. The number represents the number of milliseconds since epoch (January 1, 1970) in UTC.