private static Map<String, Expression> expressionDocumentation;

    public static Map<String, Expression> load() throws ExpressionDocumentationException {
        if (expressionDocumentation == null) {
            expressionDocumentation = new HashMap<>();

            ClassLoader docLoader = initializeDocLoader();

      <value>org.apache.maven.usability.plugin</value>
    </default>
  </defaults>
  <classes>
    <class rootElement="true" xml.tagName="paramdoc">
      <version>1.0.0</version>
      <name>ExpressionDocumentation</name>
      <description>The root of a parameter plugin expression document.</description>
      <fields>
        <field>
          <version>1.0.0</version>
          <name>expressions</name>