text: ##########################################################################
  #
  #  Copyright (c) 2012, Image Engine Design Inc. All rights reserved.
  #
  #  Redistribution and use in source and binary forms, with or without
  #  modification, are permitted provided that the following conditions are
  #  met:
  #
  #      * Redistributions of source code must retain the above
  #        copyright notice, this list of conditions and the following
  #        disclaimer.
  #
  #      * Redistributions in binary form must reproduce the above
  #        copyright notice, this list of conditions and the following
  #        disclaimer in the documentation and/or other materials provided with
  #        the distribution.
  #
  #      * Neither the name of John Haddon nor the names of
  #        any other contributors to this software may be used to endorse or
  #        promote products derived from this software without specific prior
  #        written permission.
  #
  #  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  #  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  #  THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  #  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  #  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  #  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  #  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  #  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  #  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  #  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  #  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  #
  ##########################################################################
  
  import IECore
  
  class parameterChangedCallback( IECore.Parameterised ) :
  
  	def __init__( self ) :
  
  		IECore.Parameterised.__init__( self, "" )
  
  		self.parameters().addParameters(
  
  			[
  				IECore.IntParameter(
  					"driver",
  					"",
  					0
  				),
  
  				IECore.IntParameter(
  					"driven",
  					"",
  					0
  				),
  
  			],
  
  		)
  
  		self.changes = []
  
  	def parameterChanged( self, parameter ) :
  
  		self.changes.append( ( parameter, str( parameter.getValue() ) ) )
  
  		if parameter.isSame( self.parameters()["driver"] ) :
  			self.parameters()["driven"].setNumericValue( self.parameters()["driver"].getNumericValue() * 5 )
  
  IECore.registerRunTimeTyped( parameterChangedCallback )
  