Please lord clippy

src/machine.rs

@@ -1,5 +1,8 @@
 use std::io::{Read, Write};
+use std::sync::Mutex;
+use std::rc::Rc;
 
+use Result;
 use block::Block;
 use ops::Operation;
 use ijvmreader::IJVMReader;
@@ -7,11 +10,9 @@ use binread::{BinRead, BinReadable};
 use frame::Frame;
 use stack::Stack;
 use pool::Pool;
-use netstack::NetStack;
-use Result;
-use std::sync::Mutex;
-use std::rc::Rc;
 
+#[cfg(feature = "bonus:network")]
+use netstack::NetStack;
 #[cfg(feature = "bonus:heap")]
 use heap::Heap;
 
@@ -24,8 +25,9 @@ pub struct Machine {
     pub pool: Pool,
     pub block: Block,
     pub frame: Vec<Frame>,
-    pub net: NetStack,
 
+    #[cfg(feature = "bonus:network")]
+    pub net: NetStack,
     #[cfg(feature = "bonus:heap")]
     pub heap: Heap,
 
@@ -45,6 +47,7 @@ impl Machine {
             stream_in: Box::new(::std::io::stdin()),
             stream_out: Rc::new(Mutex::new(::std::io::stdout())),
 
+            #[cfg(feature = "bonus:network")]
             net: NetStack::new(),
 
             #[cfg(feature = "bonus:heap")]