IVar: move MultipleAssignmentError into the class.

Author: chrisseaton

lib/concurrent/ivar.rb

@@ -5,9 +5,9 @@
 
 module Concurrent
 
-  MultipleAssignmentError = Class.new(StandardError)
-
   class IVar
+    MultipleAssignmentError = Class.new(StandardError)
+
     include Obligation
     include Concurrent::Observable
 

spec/concurrent/ivar_spec.rb

@@ -108,7 +108,7 @@ def trigger_observable(observable)
       it 'raises an exception if set more than once' do
         i = IVar.new
         i.set(14)
-        expect {i.set(2)}.to raise_error(MultipleAssignmentError)
+        expect {i.set(2)}.to raise_error(IVar::MultipleAssignmentError)
         i.value.should eq 14
       end
 
@@ -135,7 +135,7 @@ def trigger_observable(observable)
       it 'raises an exception if set more than once' do
         i = IVar.new
         i.fail
-        expect {i.fail}.to raise_error(MultipleAssignmentError)
+        expect {i.fail}.to raise_error(IVar::MultipleAssignmentError)
         i.value.should be_nil
       end