class @beta Efl.Core.Env extends Efl.Object implements Efl.Duplicate {
   [[This object can maintain a set of key value pairs

     A object of this type alone does not apply the object to the system.
     For getting the value into the system, see @Efl.Core.Proc_Env.

     A object can be forked, which will only copy its values, changes to the returned object will not change the object
     where it is forked off.
   ]]
   methods {
      @property env {
         [[ Stored var value pairs of this object.

            Var must contain only: underscores ('_'), letters ('a-z', 'A-Z'),
            numbers ('0-9'), but the first character may not be a number.
         ]]
         set {
            [[ Add a new pair to this object ]]
         }
         get {
            [[ Get the value of the $var, or $null if no such $var exists in the object]]
         }
         keys {
            var: string; [[ The name of the variable ]]
         }
         values {
            value: string; [[ Set var to this value if not $NULL,
                              otherwise clear this env value if value
                              is $NULL or if it is an empty string ]]
         }
      }
      unset {
         [[ Remove the pair with the matching $var from this object]]
         params {
           var : string; [[ The name of the variable ]]
         }
      }
      clear {
         [[ Remove all pairs from this object]]
      }
      @property content {
        [[ Get the content of this object.

          This will return a iterator that contains all keys that are part of this object.
        ]]
        get {

        }
        values {
          iter : iterator<string> @move;
        }
      }
   }
   implements {
      Efl.Object.constructor;
      Efl.Duplicate.duplicate;
   }
}