code: protected void unpackDependentXars(Artifact artifact) throws MojoExecutionException
      {
          try {
              Set<Artifact> dependencies = resolveArtifactDependencies(artifact);
              for (Artifact dependency : dependencies) {
                  unpack(dependency.getFile(), this.outputDirectory, "XAR Plugin", false, getIncludes(), getExcludes());
              }
          } catch (Exception e) {
              throw new MojoExecutionException(String.format("Failed to unpack artifact [%s] dependencies", artifact), e);
          }
      }
docs: Unpack xar dependencies of the provided artifact.
  
  @throws MojoExecutionException error when unpack dependencies.