set Style Source Property
Sets a value to a style source property. Note: When setting the `data` property of a `geojson` source, this method does not synchronously parse the GeoJSON data. The events API shall be used to make sure the provided GeoJSON data is valid. In case the GeoJSON is valid, a `map-loaded` event will be propagated. In case of errors, a `map-loading-error` event will be propagated instead.
Return
A string describing an error if the operation was not successful, empty otherwise.
Parameters
source Id
A style source identifier.
property
The style source property name.
value
The style source property value.