pub fn child_storage(&self, storage_key: &[u8], key: &[u8]) -> Result<Option<Vec<u8>>, String> {
		let root = self.storage(storage_key)?.unwrap_or(default_child_trie_root::<H>(storage_key));

		let mut read_overlay = S::Overlay::default();
		let eph = Ephemeral {
			storage: &self.storage,
			overlay: &mut read_overlay,
		};

		let map_e = |e| format!("Trie lookup error: {}", e);

		read_child_trie_value(storage_key, &eph, &root, key).map_err(map_e)
	}
/// Get the value of child storage at given key.
Get the value of child storage at given key.
Get the value of child storage at given key .
pub fn child_storage(&self, storage_key: &[u8], key: &[u8]) -> Result<Option<Vec<u8>>, String> {
		let root = self.storage(storage_key)?.unwrap_or(default_child_trie_root::<H>(storage_key));
		let mut read_overlay = S::Overlay::default();
		let eph = Ephemeral {
			storage: &self.storage,
			overlay: &mut read_overlay,
		};
		let map_e = |e| format!("Trie lookup error: {}", e);
		read_child_trie_value(storage_key, &eph, &root, key).map_err(map_e)
	}
pub fn child_storage ( & self , storage_key : & [ u8 ] , key : & [ u8 ] ) -> Result < Option < Vec < u8 > > , String > { let root = self . storage ( storage_key ) ? . unwrap_or ( default_child_trie_root :: < H > ( storage_key ) ) ; let mut read_overlay = S :: Overlay :: default ( ) ; let eph = Ephemeral { storage : & self . storage , overlay : & mut read_overlay , } ; let map_e = | e | format ! ( " " e ) ; read_child_trie_value ( storage_key , & eph , & root , key ) . map_err ( map_e ) }
Get the value of child storage at given key.
Get the value of child storage at given key .
&self
storage_key
&[u8]
key
&[u8]
&self
storage_key
&[u8]
key
&[u8]