diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index 59cc71af..11bc62f0 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -1289,114 +1289,6 @@ def put_string(str)
       end
     end
 
-    def validate_data(data)
-      case data
-      when nil
-      when String
-      when Integer
-        NumValidator.ensure_number(data)
-      when Array
-        if data[0] == 'CHANGEDSINCE'
-          NumValidator.ensure_mod_sequence_value(data[1])
-        else
-          data.each do |i|
-            validate_data(i)
-          end
-        end
-      when Time
-      when Symbol
-      else
-        data.validate
-      end
-    end
-
-    def send_data(data, tag = nil)
-      case data
-      when nil
-        put_string("NIL")
-      when String
-        send_string_data(data, tag)
-      when Integer
-        send_number_data(data)
-      when Array
-        send_list_data(data, tag)
-      when Time
-        send_time_data(data)
-      when Symbol
-        send_symbol_data(data)
-      else
-        data.send_data(self, tag)
-      end
-    end
-
-    def send_string_data(str, tag = nil)
-      case str
-      when ""
-        put_string('""')
-      when /[\x80-\xff\r\n]/n
-        # literal
-        send_literal(str, tag)
-      when /[(){ \x00-\x1f\x7f%*"\\]/n
-        # quoted string
-        send_quoted_string(str)
-      else
-        put_string(str)
-      end
-    end
-
-    def send_quoted_string(str)
-      put_string('"' + str.gsub(/["\\]/n, "\\\\\\&") + '"')
-    end
-
-    def send_literal(str, tag = nil)
-      synchronize do
-        put_string("{" + str.bytesize.to_s + "}" + CRLF)
-        @continued_command_tag = tag
-        @continuation_request_exception = nil
-        begin
-          @continuation_request_arrival.wait
-          e = @continuation_request_exception || @exception
-          raise e if e
-          put_string(str)
-        ensure
-          @continued_command_tag = nil
-          @continuation_request_exception = nil
-        end
-      end
-    end
-
-    def send_number_data(num)
-      put_string(num.to_s)
-    end
-
-    def send_list_data(list, tag = nil)
-      put_string("(")
-      first = true
-      list.each do |i|
-        if first
-          first = false
-        else
-          put_string(" ")
-        end
-        send_data(i, tag)
-      end
-      put_string(")")
-    end
-
-    DATE_MONTH = %w(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec)
-
-    def send_time_data(time)
-      t = time.dup.gmtime
-      s = format('"%2d-%3s-%4d %02d:%02d:%02d +0000"',
-                 t.day, DATE_MONTH[t.month - 1], t.year,
-                 t.hour, t.min, t.sec)
-      put_string(s)
-    end
-
-    def send_symbol_data(symbol)
-      put_string("\\" + symbol.to_s)
-    end
-
     def search_internal(cmd, keys, charset)
       if keys.instance_of?(String)
         keys = [RawData.new(keys)]
diff --git a/lib/net/imap/command_data.rb b/lib/net/imap/command_data.rb
index 8dd36cd5..d52390c9 100644
--- a/lib/net/imap/command_data.rb
+++ b/lib/net/imap/command_data.rb
@@ -3,6 +3,115 @@
 module Net
   class IMAP < Protocol
 
+    private
+
+    def validate_data(data)
+      case data
+      when nil
+      when String
+      when Integer
+        NumValidator.ensure_number(data)
+      when Array
+        if data[0] == 'CHANGEDSINCE'
+          NumValidator.ensure_mod_sequence_value(data[1])
+        else
+          data.each do |i|
+            validate_data(i)
+          end
+        end
+      when Time
+      when Symbol
+      else
+        data.validate
+      end
+    end
+
+    def send_data(data, tag = nil)
+      case data
+      when nil
+        put_string("NIL")
+      when String
+        send_string_data(data, tag)
+      when Integer
+        send_number_data(data)
+      when Array
+        send_list_data(data, tag)
+      when Time
+        send_time_data(data)
+      when Symbol
+        send_symbol_data(data)
+      else
+        data.send_data(self, tag)
+      end
+    end
+
+    def send_string_data(str, tag = nil)
+      case str
+      when ""
+        put_string('""')
+      when /[\x80-\xff\r\n]/n
+        # literal
+        send_literal(str, tag)
+      when /[(){ \x00-\x1f\x7f%*"\\]/n
+        # quoted string
+        send_quoted_string(str)
+      else
+        put_string(str)
+      end
+    end
+
+    def send_quoted_string(str)
+      put_string('"' + str.gsub(/["\\]/n, "\\\\\\&") + '"')
+    end
+
+    def send_literal(str, tag = nil)
+      synchronize do
+        put_string("{" + str.bytesize.to_s + "}" + CRLF)
+        @continued_command_tag = tag
+        @continuation_request_exception = nil
+        begin
+          @continuation_request_arrival.wait
+          e = @continuation_request_exception || @exception
+          raise e if e
+          put_string(str)
+        ensure
+          @continued_command_tag = nil
+          @continuation_request_exception = nil
+        end
+      end
+    end
+
+    def send_number_data(num)
+      put_string(num.to_s)
+    end
+
+    def send_list_data(list, tag = nil)
+      put_string("(")
+      first = true
+      list.each do |i|
+        if first
+          first = false
+        else
+          put_string(" ")
+        end
+        send_data(i, tag)
+      end
+      put_string(")")
+    end
+
+    DATE_MONTH = %w(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec)
+
+    def send_time_data(time)
+      t = time.dup.gmtime
+      s = format('"%2d-%3s-%4d %02d:%02d:%02d +0000"',
+                 t.day, DATE_MONTH[t.month - 1], t.year,
+                 t.hour, t.min, t.sec)
+      put_string(s)
+    end
+
+    def send_symbol_data(symbol)
+      put_string("\\" + symbol.to_s)
+    end
 
     class RawData # :nodoc:
       def send_data(imap, tag)