Gst.Caps.prototype.merge

function merge(caps2:Gst.Caps):Gst.Caps {
    // Gjs wrapper for gst_caps_merge()
}

Appends the structures contained in caps2 to caps1 if they are not yet expressed by caps1. The structures in caps2 are not copied -- they are transferred to a writable copy of caps1, and then caps2 is freed. If either caps is ANY, the resulting caps will be ANY.