Still include SetOutput as it is exported

This reverts commit 6291af1f4d.

command.go

@@ -218,6 +218,14 @@ func (c *Command) SetArgs(a []string) {
 	c.args = a
 }
 
+// SetOutput sets the destination for usage and error messages.
+// If output is nil, os.Stderr is used.
+// Deprecated: Use SetOut and/or SetErr instead
+func (c *Command) SetOutput(output io.Writer) {
+	c.outWriter = output
+	c.errWriter = output
+}
+
 // SetOut sets the destination for usage messages.
 // If newOut is nil, os.Stdout is used.
 func (c *Command) SetOut(newOut io.Writer) {

command_test.go

@@ -1557,6 +1557,14 @@ func TestEnableCommandSortingIsDisabled(t *testing.T) {
 	EnableCommandSorting = true
 }
 
+func TestSetOutput(t *testing.T) {
+	c := &Command{}
+	c.SetOutput(nil)
+	if out := c.OutOrStdout(); out != os.Stdout {
+		t.Errorf("Expected setting output to nil to revert back to stdout")
+	}
+}
+
 func TestSetOut(t *testing.T) {
 	c := &Command{}
 	c.SetOut(nil)