   """
   @spec with_exp(Token.t) :: Token.t
   def with_exp(token = %Token{claims: claims}) do
-    %{ token | claims: Map.put(claims, :exp, get_current_time + (2 * 60 * 60 * 1000)) }
+    %{ token | claims: Map.put(claims, :exp, current_time + (2 * 60 * 60 * 1000)) }
   end
 
   @doc """

  """
  @spec with_nbf(Token.t) :: Token.t
  def with_nbf(token = %Token{claims: claims}) do
    %{ token | claims: Map.put(claims, :nbf, get_current_time - 100) }
  end

  @doc """

  """
  @spec with_iat(Token.t) :: Token.t
  def with_iat(token = %Token{claims: claims}) do
    %{ token | claims: Map.put(claims, :iat, current_time) }
  end
  @doc """
  Adds `:iat` claim with a given value.
