testPlugin = plugin;
            }

            Integer count = validPluginCounts.get(pluginArtifactId);

            assertEquals(0, (int) count, "Multiple copies of plugin: " + pluginArtifactId + " found in POM.");

            count = count + 1;

            validPluginCounts.put(pluginArtifactId, count);
        }

        assertNotNull(testPlugin);

 * <p>
 * This builder uses a number of threads equal to the minimum of the degree of concurrency (which is the thread count
 * set with <code>-T</code> on the command-line) and the number of projects to build. As such, building a single project
 * will always result in a sequential build, regardless of the thread count.
 * </p>
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 *