text: #ifndef _MDataBlock
  #define _MDataBlock
  //-
  // ==========================================================================
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  // rights reserved.
  //
  // The coded instructions, statements, computer programs, and/or related
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  // including the above license grant, this restriction and the following
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  //+
  //
  // CLASS:    MDataBlock
  //
  // ****************************************************************************
  
  #if defined __cplusplus
  
  // ****************************************************************************
  // INCLUDED HEADER FILES
  
  
  #include <maya/MStatus.h>
  #include <maya/MTypes.h>
  #include <maya/MDataHandle.h>
  #include <maya/MArrayDataHandle.h>
  
  // ****************************************************************************
  // FORWARD DECLARATIONS
  
  class MObject;
  class MPlug;
  class MDGContext;
  
  // ****************************************************************************
  // CLASS DECLARATION (MDataBlock)
  
  //! \ingroup OpenMaya
  //! \brief Dependency node data block. 
  /*!
  An MDataBlock provides storage for the data being received by or sent by the
  node.  It is the data for the plugs and attributes of the node.  The data
  block is only valid during the compute method of the depend node.  Pointers to
  the data block should not be retained after the compute method.
  
  Access to the data in an MDataBlock is done using an MDataHandle or an
  MArrayDataHandle.
  */
  class OPENMAYA_EXPORT MDataBlock
  {
  
  public:
  
  	virtual		     ~MDataBlock ();
  	MDataHandle      inputValue ( const MPlug & plug,
  								        MStatus * ReturnStatus = NULL );
  	MDataHandle      inputValue ( const MObject & attribute,
  								        MStatus * ReturnStatus = NULL );
  	MDataHandle      outputValue ( const MPlug & plug,
  								        MStatus * ReturnStatus = NULL );
  	MDataHandle      outputValue ( const MObject & attribute,
  								        MStatus * ReturnStatus = NULL );
  	MArrayDataHandle inputArrayValue ( const MPlug & plug,
  								        MStatus * ReturnStatus = NULL );
  	MArrayDataHandle inputArrayValue ( const MObject & attribute,
  								        MStatus * ReturnStatus = NULL );
  	MArrayDataHandle outputArrayValue ( const MPlug & plug,
  										MStatus * ReturnStatus = NULL );
  	MArrayDataHandle outputArrayValue ( const MObject & attribute,
  										MStatus * ReturnStatus = NULL );
  	MStatus          setClean ( const MPlug & plug );
  	MStatus          setClean ( const MObject & attribute );
  
  	bool			isClean ( const MPlug & plug );
  	bool			isClean ( const MObject & attribute,
  							  MStatus* ReturnStatus=NULL );
  
  	MDGContext       context ( MStatus * ReturnStatus = NULL );
  	MStatus          setContext ( const MDGContext & ctx );
  
  	static const char*	className();
  
  protected:
  // No protected members
  
  private:
  	friend class MArrayDataBuilder;
      friend class MEvaluationNode;
  
  	friend class MPxNode;
  	friend class MPxAssembly;	// can be removed after MAYA-15346 is fixed
  	friend class MPlug;
  	MDataBlock( void * ptr );
  	void * data;
  };
  
  #endif /* __cplusplus */
  #endif /* _MDataBlock */
  