nl_tokens: Mixin the target with the source
pl_tokens: function doMixin ( target , source , k , opts ) { let { mixinAttrName = MIXIN_ATTR_NAME , lifecycleHookMap , mixinStrategy } = opts ; if ( k === mixinAttrName ) { return ; } let mixinHandler = mixinStrategy && mixinStrategy [ k ] ; if ( mixinHandler ) { target [ k ] = mixinHandler ( target [ k ] , source [ k ] ) ; } else if ( lifecycleHookMap [ k ] ) { let child = target [ k ] ; let parent = source [ k ] ; if ( ! Array . isArray ( child ) ) { child = child ? [ child ] : [ ] ; } if ( ! Array . isArray ( parent ) ) { parent = parent ? [ parent ] : [ ] ; } child . unshift . apply ( child , parent ) ; <mask> [ k ] = child ; } else if ( ! target . hasOwnProperty ( k ) ) { target [ k ] = source [ k ] ; } }