Support custom command in pipeline

pipeline.go

@@ -31,6 +31,12 @@ type Pipeline struct {
 	closed bool
 }
 
+func (c *Pipeline) Do(args ...interface{}) *Cmd {
+	cmd := NewCmd(args...)
+	_ = c.Process(cmd)
+	return cmd
+}
+
 // Process queues the cmd for later execution.
 func (c *Pipeline) Process(cmd Cmder) error {
 	c.mu.Lock()

pipeline_test.go

@@ -60,6 +60,13 @@ var _ = Describe("pipelining", func() {
 			Expect(err).NotTo(HaveOccurred())
 			Expect(val).To(Equal("value"))
 		})
+
+		It("supports custom command", func() {
+			pipe.Do("ping")
+			cmds, err := pipe.Exec()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(cmds).To(HaveLen(1))
+		})
 	}
 
 	Describe("Pipeline", func() {