functions/system/Get-DMCallback.ps1

function Get-DMCallback
{
    <#
    .SYNOPSIS
        Returns the list of registered callbacks.
     
    .DESCRIPTION
        Returns the list of registered callbacks.
 
        For more details on this system, call:
        Get-Help about_DM_callbacks
     
    .PARAMETER Name
        The name of the callback.
        Supports wildcard filtering.
     
    .EXAMPLE
        PS C:\> Get-DMCallback
 
        Returns a list of all registered callbacks
    #>

    [CmdletBinding()]
    Param (
        [string]
        $Name = '*'
    )
    
    process
    {
        $script:callbacks.Values | Where-Object Name -like $Name
    }
}