Make LazyMultiError only constructable via function

common/errors/lazymultierror_test.go

Index: common/errors/lazymultierror_test.go
diff --git a/common/errors/multierror_test.go b/common/errors/lazymultierror_test.go
similarity index 57%
copy from common/errors/multierror_test.go
copy to common/errors/lazymultierror_test.go
index a7a15329e1f430accde5798033af90a1a3d0b129..c75630047cb56483d28b0b88d3e9049bdc36ddf1 100644
--- a/common/errors/multierror_test.go
+++ b/common/errors/lazymultierror_test.go
@@ -12,60 +12,11 @@ import (
 	. "github.com/smartystreets/goconvey/convey"
 )
 
-type otherMEType []error
-
-func (o otherMEType) Error() string { return "FAIL" }
-
-func TestUpstreamErrors(t *testing.T) {
-	t.Parallel()
-
-	Convey("Test MultiError", t, func() {
-		Convey("nil", func() {
-			me := MultiError(nil)
-			So(me.Error(), ShouldEqual, "(0 errors)")
-			Convey("single", func() {
-				So(SingleError(error(me)), ShouldBeNil)
-			})
-		})
-		Convey("one", func() {
-			me := MultiError{errors.New("sup")}
-			So(me.Error(), ShouldEqual, "sup")
-		})
-		Convey("two", func() {
-			me := MultiError{errors.New("sup"), errors.New("what")}
-			So(me.Error(), ShouldEqual, "sup (and 1 other error)")
-		})
-		Convey("more", func() {
-			me := MultiError{errors.New("sup"), errors.New("what"), errors.New("nerds")}
-			So(me.Error(), ShouldEqual, "sup (and 2 other errors)")
-
-			Convey("single", func() {
-				So(SingleError(error(me)), ShouldResemble, errors.New("sup"))
-			})
-		})
-	})
-
-	Convey("SingleError passes through", t, func() {
-		e := errors.New("unique")
-		So(SingleError(e), ShouldEqual, e)
-	})
-
-	Convey("Test MultiError Conversion", t, func() {
-		ome := otherMEType{errors.New("sup")}
-		So(Fix(ome), ShouldHaveSameTypeAs, MultiError{})
-	})
-
-	Convey("Fix passes through", t, func() {
-		e := errors.New("unique")
-		So(Fix(e), ShouldEqual, e)
-	})
-}
-
 func TestLazyMultiError(t *testing.T) {
 	t.Parallel()
 
 	Convey("Test LazyMultiError", t, func() {
-		lme := LazyMultiError{Size: 10}
+		lme := NewLazyMultiError(10)
 		So(lme.Get(), ShouldEqual, nil)
 
 		e := errors.New("sup")
@@ -80,7 +31,7 @@ func TestLazyMultiError(t *testing.T) {
 		So(func() { lme.Assign(20, e) }, ShouldPanic)
 
 		Convey("Try to freak out the race detector", func() {
-			lme := LazyMultiError{Size: 64}
+			lme := NewLazyMultiError(64)
 			Convey("all nils", func() {
 				wg := sync.WaitGroup{}
 				for i := 0; i < 64; i++ {