function Get-ServersByPod {
    param (
        [Parameter(Mandatory = $false)]
        [Alias('Environment')]
        [ValidateScript({Assert-ValidAWSProfileName -ProfileName $_ -ArgumentValidationScript})]
        $ProfileName = (Get-LocalCachedAWSProfile),
        [Parameter(Mandatory = $true)]
        [ArgumentCompleter( {
            param ( $commandName,
                    $parameterName,
                    $wordToComplete,
                    $commandAst,
                    $fakeBoundParameters )
            $p = $fakeBoundParameters.ProfileName
            if ([string]::IsNullOrWhiteSpace($p)) {
                $p = (Get-LocalCachedAWSProfile)
            }
            $s = Get-CachedInstances -ProfileName $p
            return $s.Designation | Sort-Object | Get-Unique
        } )]
        [string]$Designation
    )

    return (Get-CachedInstances -ProfileName $ProfileName).Where({$_.Designation -eq $Designation})
}