This is the v1 version, had the v2 before.

literal.go

@@ -0,0 +1,13 @@
+package imap
+
+import (
+	"io"
+)
+
+// A literal, as defined in RFC 3501 section 4.3.
+type Literal interface {
+	io.Reader
+
+	// Len returns the number of bytes of the literal.
+	Len() int
+}