/**
     * Set the goals to execute within the phase.
     *
     * @param executions a executions object.
     */
    public void setExecutions(java.util.List<Execution> executions) {
        this.executions = executions;
    } // -- void setExecutions( java.util.List )

    /**
     * Set the ID of this phase, e.g.,
     * <code>generate-sources</code>.
     *
     * @param id a id object.

            } else {
                index.put(key, plugin);
            }

            Set<String> executionIds = new HashSet<>();

            for (PluginExecution exec : plugin.getExecutions()) {
                if (!executionIds.add(exec.getId())) {
                    addViolation(
                            problems,
                            Severity.ERROR,
                            Version.V20,