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: handle_set_map.rs
    path of file: ./repos/wgpu/naga/src/compact
    
    the code of the file until where you have to start completion: use crate::arena::{Arena, Handle, Range, UniqueArena};

type Index = std::num::NonZeroU32;

/// A set of `Handle<T>` values.
pub struct HandleSet<T> {
    /// Bound on zero-based indexes of handles stored in this set.
    len: usize,

    /// `members[i]` is true if the handle with zero-based index `i`
    /// is a member.
    members: bit_set::BitSet,

    /// This type is indexed by values of type `T`.
    as_keys: std::marker::PhantomData<T>,
}

impl<T> HandleSet<T> {
    pub fn for_arena(arena: &impl ArenaType
    
    pub fn adjust_range(&self, range: &mut Range<T>, compacted_arena: &Arena<T>) {
        let mut index_range = range.zero_based_index_range();
        let compacted;
        // Remember that the indices we retrieve from `new_index` are 1-based
        // compacted indices, but the index range we're computing is zero-based
        // compacted indices.
        if let Some(first1) = index_range.find_map(|i| self.new_index[i as usize]) {
            // The first call to `find_map` mutated `index_range` to hold the
            // remainder of original range, which is exactly the range we need
            // to search for the new last handle.
            if let Some(last1) = index_range.rev().find_map(|i| self.new_index[i as usize]) {
                // Build a zero-based end-exclusive range, given one-based handle indices.
                compacted = first1.get() - 1..last1.get();
            } else {
                // The range contains only a single live handle, which
                // we identified with the first `find_map` call.
                compacted = first1.get() - 1..first1.get();
            }
        } else {
            compacted = 0..0;
        };
        *range = Range::from_zero_based_index_range(compacted, compacted_arena);
    }