if_chain! {
if let ExprKind::MethodCall(method_name, _, exprs, _) = expr.kind;
if method_name.ident.as_str() == "read_to_string";
if let ExprKind::Path(QPath::Resolved(None, _)) = &exprs[0].kind;
if_chain! {
if let ExprKind::MethodCall(method_name, _, exprs, _) = expr.kind;
if method_name.ident.as_str() == "read_to_string";
if let ExprKind::Path(QPath::Resolved(None, _)) = &exprs[0].kind;