function Get-Vlan {
    <#
        .SYNOPSIS

        Return vlan object.

        .DESCRIPTION

        Return vlan object by vlanId, vlan number, l2domainId (return all vlans in domain), subnet object or l2domain object

        .PARAMETER Number
        Vlan tag
    #>
    [CmdletBinding(DefaultParameterSetName="NoParams")]
    [OutputType([PS.IPAM.Vlan])]
    param (
        [parameter(
            Mandatory=$true,
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position=0,
            ParameterSetName="ByID"
        )]
        [ValidateNotNullOrEmpty()]
        [int]
        $Id,
        [parameter(
            Mandatory=$true,
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position=0,
            ParameterSetName="ByNumber"
        )]
        [ValidateNotNullOrEmpty()]
        [int]
        $Number,
        [parameter(
            Mandatory=$true,
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position=0,
            ParameterSetName="ByL2Domain"
        )]
        [ValidateNotNullOrEmpty()]
        [int]
        $L2DomainId,
        [parameter(
            Mandatory=$false,
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position=0,
            ParameterSetName="BySubnetObject"
        )]
        [ValidateNotNullOrEmpty()]
        [PS.IPAM.Subnetwork]
        $SubnetObject,
        [parameter(
            Mandatory=$false,
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position=0,
            ParameterSetName="ByDomainObject"
        )]
        [ValidateNotNullOrEmpty()]
        [PS.IPAM.Domain]
        $DomainObject
    )
    process {
        $_params = @{
            Controller = [PS.IPAM.controllers]::vlan
            Method     = "GET"
            Type       = [PS.IPAM.types]::Vlan
        }
        switch ($PSCmdlet.ParameterSetName) {
            "ByID"      { $_identifiers = @($Id); break }
            "ByNumber"  { $_identifiers = @("search",$Number); break }
            "ByL2Domain"{
                $_params.Item("Controller") = [PS.IPAM.controllers]::l2domains

                $_l2domainId = $L2DomainId

                $_identifiers = @($_l2domainId,[PS.IPAM.subcontrollers]::vlans)
                break
            }
            "BySubnetObject" {
                if ($SubnetObject.VlanId) {
                    $_identifiers = @($SubnetObject.VlanId); break
                } else {
                    return $null
                }
            }
            "DomainObject" {
                Get-Vlan -L2DomainId $DomainObject.Id
            }
        }
        $_params.Add("Identifiers",$_identifiers)

        Invoke-Request @_params
    }
}
Export-ModuleMember -Function Get-Vlan