(PECL event >= 1.4.0-beta)
EventHttpRequest::findHeader — Finds the value belonging a header
$key
   , 
    string
     $type
   ): voidFinds the value belonging a header.
key
    The header name.
type
    
      One of
      
       EventHttpRequest::*_HEADER constants
      .
     
   Returns null if header not found.