Bug 153853 [Regression]The bound column names must be unique within the entire table.
Regression case Regression_136421(under org.eclipse.birt.report.tests.model) failed. Expected result: Model will avoid adding a duplicate bound column name within a table.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleHandle.java
Library library = (Library) iter.next( );
			retLibs.add( library.handle( ) );
		}
		return Collections.unmodifiableList( retLibs );
	}
	/**
	 * Returns the libraries this report design includes directly. Each in the
	 * returned list is the instance of <code>LibraryHandle</code>.
	 * 
	 * @return the libraries this report design includes directly.
	 */
	public List getLibraries( )
	{
		return getLibraries( IModuleNameScope.DIRECTLY_INCLUDED_LEVEL );
	}
	/**
	 * Returns the library handle with the given namespace.
	 * 
	 * @param namespace
	 *            the library namespace
	 * @return the library handle with the given namespace
	 */
	public LibraryHandle getLibrary( String namespace )
	{
		Module library = module.getLibraryWithNamespace( namespace,
				IModuleNameScope.DIRECTLY_INCLUDED_LEVEL );
		if ( library == null )
			return null;
		return (LibraryHandle) library.getHandle( library );
	}