code: protected boolean isBuildNeeded()
              throws MojoExecutionException {
          File outDir = getOutputDirectory();
          return hasNoPreviousBuild(outDir) || hasArgumentsChanged(outDir) ||
                  hasSourcesChanged(outDir) || hasNonWeavedClassesChanged(outDir);
  
      }
docs: Checks modifications that would make us need a build
  
  @return <code>true</code> if build is needed, otherwise <code>false</code>
  @throws MojoExecutionException