Public/Crypto/Resolve-MemberOwnerType.ps1

function Resolve-MemberOwnerType {
  [CmdletBinding()]
  param(
    [Parameter(Position = 0)]
    [System.Management.Automation.PSMethod]$Method
  )

  # TODO: support overloads, support interface definitions

  $PSCmdlet.WriteVerbose("Resolving owning type of '$($Method.Name)'.")

  # hackety-hack - this is prone to breaking in the future
  $TargetType = [System.Management.Automation.PSMethod].GetField("baseObject", "Instance,NonPublic").GetValue($Method)
  if (($TargetType -isnot [System.Type]) -and (!$TargetType.__CLASS)) {
    $TargetType = $TargetType.GetType()
  }

  if ($TargetType -is [System.Management.ManagementObject]) {
    $DeclaringType = Get-CimClass $TargetType.__CLASS -Namespace $TargetType.__NAMESPACE
  } else {
    if ($Method.OverloadDefinitions -match "static") {
      $Flags = "Static,Public"
    } else {
      $Flags = "Instance,Public"
    }

    # TODO: support overloads
    $MethodInfo = $TargetType.GetMethods($Flags) | Where-Object { $_.Name -eq $Method.Name } | Select-Object -First 1

    if (!$MethodInfo) {
      # this shouldn't happen.
      throw "Could not resolve owning type."
    }

    $DeclaringType = $MethodInfo.DeclaringType
  }

  $PSCmdlet.WriteVerbose("Owning type is $($TargetType.FullName). Method declared on $($DeclaringType.FullName).")
  $DeclaringType
}