let mut f = |h, from, to, flag| changes.has_edge(h, from, to, flag);

            &mut f,

    apply_change_to_channel(
        |h, from, to, flag| changes.has_edge(h, from, to, flag),
        txn,
        &mut channel,
        internal,
        &hash,
        &change,
        workspace,
    )

    apply_change_to_channel(txn, &mut channel, internal, &hash, &change, workspace)

                apply_change_to_channel(
                    |h, from, to, flag| changes.has_edge(h, from, to, flag),
                    txn,
                    &mut channel,
                    internal,
                    &hash,
                    &change,
                    workspace,
                )?;

                apply_change_to_channel(txn, &mut channel, internal, &hash, &change, workspace)?;

fn apply_change_to_channel<
    T: MutTxnT,
    F: FnMut(
        Hash,
        Position<Option<Hash>>,
        Position<Option<Hash>>,
        EdgeFlags,
    ) -> Result<bool, anyhow::Error>,
>(
    mut changes: F,

fn apply_change_to_channel<T: MutTxnT>(

                                &mut changes,

                                &mut changes,

// org id 7IPbKRayK1ey50vdV6FP2KOmzRGn2tCT3qapFICvlNc=

    // org id GEylov+bdcaQUmngYlibUCe0K6dMYx9lmeEmNPGCFUQ=

    // org id O9lNVqhAbRqj2tE6JW0Ax8U3WSetv22rYrSXHQlT78A=
    let n = apply_change_to_channel(
        |_, _, _, _| Ok(true),
        txn,
        &mut channel,
        internal,
        &hash,
        &change,
        workspace,
    )?;
    // org id w0Bu10TO1Kbn1WbRcFHyU/0xBR4Yi61jj66D/1uiicM=

    let n = apply_change_to_channel(txn, &mut channel, internal, &hash, &change, workspace)?;

pub(crate) fn put_newedge<T, C, F>(
    mut validate_edge: C,

pub(crate) fn put_newedge<T, F>(

    C: FnMut(
        Hash,
        Position<Option<Hash>>,
        Position<Option<Hash>>,
        EdgeFlags,
    ) -> Result<bool, anyhow::Error>,

        if !del {
            if let Some(intro) = n.introduced_by {
                // Check that the edge actually existed at some point.
                if !validate_edge(intro, n.from, n.to.start_pos(), n.previous)? {
                    debug!("edge doesn't exist: {:?}", n);
                    return Err(crate::Error::InconsistentChange.into());
                }
            }
        }