Fix tests

runtime/src/validate_block/implementation.rs

@@ -23,7 +23,6 @@ use runtime_primitives::traits::{
 use executive::ExecuteBlock;
 
 use substrate_trie::{MemoryDB, read_trie_value, delta_trie_root};
-use codec::Decode;
 
 use rstd::{slice, ptr, cmp, vec::Vec, boxed::Box, mem};
 
@@ -59,6 +58,8 @@ trait Storage {
 pub fn validate_block<B: BlockT, E: ExecuteBlock<B>>(
 	mut arguments: &[u8],
 ) {
+	use codec::Decode;
+
 	let (parent_hash, block_data): (B::Hash, crate::ParachainBlockData::<B>) = Decode::decode(&mut arguments)
 		.expect("Could not decode parachain block.");
 	// TODO: Add `PolkadotInherent`.