| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. | 
    | golang.org/x/debug | Package debug provides the portable interface to a program being debugged. | 
    | golang.org/x/debug/server/protocol | Package protocol defines the types used to represent calls to the debug server. | 
    | io | Package io provides basic interfaces to I/O primitives. | 
    | net/rpc | Package rpc provides access to the exported methods of an object across a network or other I/O connection. | 
    | os | Package os provides a platform-independent interface to operating system functionality. | 
    | os/exec | Package exec runs external commands. |