You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: unit_return_expecting_ord.rs
    path of file: ./repos/rust-clippy/clippy_lints/src
    
    the code of the file until where you have to start completion: use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
use rustc_hir::def_id::DefId;
use rustc_hir::{Closure, Expr, ExprKind, StmtKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty;
use rustc_middle::ty::{ClauseKind, GenericPredicates, ProjectionPredicate, TraitPredicate};
use rustc_session::declare_lint_pass;
use rustc_span::{sym, BytePos, Span};

declare_clippy_lint! {
    /// ### What it does
    /// Checks for functions that expect closures of type
    /// Fn(...) -> Ord where the implemented closure returns the unit type.
    /// The lint also suggests to remove the semi-colon at the end of the statement if present.
    ///
    /// ### Why is this bad?
    /// Likely, returning the unit type is unintentional, and
    /// could simply be caused by an extra semi-colon. Since () implements Ord
    /// it doesn't cause a compilation error.
    /// This is the same reasoning behind the unit_cmp lint.
    ///
    /// ### Known problems
    /// If returning unit is intentional, then there is no
   
    
    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
        if let ExprKind::MethodCall(_, receiver, args, _) = expr.kind {
            let arg_indices = get_args_to_check(cx, expr);
            let args = std::iter::once(receiver).chain(args.iter()).collect::<Vec<_>>();
            for (i, trait_name) in arg_indices {
                if i < args.len() {
                    match check_arg(cx, args[i]) {
                        Some((span, None)) => {
                            span_lint(
                                cx,
                                UNIT_RETURN_EXPECTING_ORD,
                                span,
                                &format!(
                                    "this closure returns \
                                   the unit type which also implements {trait_name}"
                                ),
                            );
                        },
                        Some((span, Some(last_semi))) => {
                            span_lint_and_help(
                                cx,
                                UNIT_RETURN_EXPECTING_ORD,
                                span,
                                &format!(
                                    "this closure returns \
                                   the unit type which also implements {trait_name}"
                                ),
                                Some(last_semi),
                                "probably caused by this trailing semicolon",
                            );
                        },
                        None => {},
                    }
                }
            }
        }
    }