title: cannot process argument transformation on parameter 'Tests'
body: <p>cannot convert value to type System.String : ParameterArgumentTransformationError</p>
  
  <pre><code>Param(
      # Use this flag to attach a debugger
      [switch]$AttachDebugger,
  
      # Use this flag to run the test outside of razzle window (in which case, all required file should be in the same dir)
      [switch]$NoRazzle,
  
      # Optional test specifier.
      [ValidateNotNullOrEmpty()]
      [string]$Tests,
  
      # Optional category
      [ValidateNotNullOrEmpty()]
      [string]$Category
  )
  
  $command = "Run-Tests.ps1"
  $arguments = @("-Type", "Group")
  if($AttachDebugger)
  {
      $arguments += ("-AttachDebugger")
  }
  if($NoRazzle)
  {
      $arguments += ("-NoRazzle")
  }
  if (![string]::IsNullOrWhiteSpace($Category))
  {
      $arguments += ("-Category", "$Category")
  }
  if (![string]::IsNullOrWhiteSpace($Tests))
  {
      $arguments += ("-Tests", "$Tests")
  }
  &amp; "$PSScriptRoot\Run-Tests" $arguments
  </code></pre>
  
  <p>$Tests in Run-Tests is of datatype string. How to tackle this?</p>