Returns a feature containing the union of the geometries of two features.
The feature containing the geometry used as the left operand of the operation. The properties of the result will be copied from this object.
The feature containing the geometry used as the right operand of the operation. The properties of this object are ignored.
|ErrorMargin, default: null|
The maximum amount of error tolerated when performing any necessary reprojection.
|Projection, default: null|
The projection in which to perform the operation. If not specified, the operation will be performed in a spherical coordinate system, and linear distances will be in meters on the sphere.