code: public Collection<File> getClasspath( String scope )
          throws MojoExecutionException
      {
          try
          {
              Collection<File> files = classpathBuilder.buildClasspathList( getProject(), scope, getProjectArtifacts(), isGenerator() );
  
              if ( getLog().isDebugEnabled() )
              {
                  getLog().debug( "GWT SDK execution classpath :" );
                  for ( File f : files )
                  {
                      getLog().debug( "   " + f.getAbsolutePath() );
                  }
              }
              return files;
          }
          catch ( ClasspathBuilderException e )
          {
              throw new MojoExecutionException( e.getMessage(), e );
          }
      }
docs: Build the GWT classpath for the specified scope
  
  @param scope Artifact.SCOPE_COMPILE or Artifact.SCOPE_TEST
  @return a collection of dependencies as Files for the specified scope.
  @throws MojoExecutionException if classPath building failed