code: private String parse(DocumentContext document) throws ParseException {
      if (document.namespaceDeclaration() != null) {
        setCurrentNamespace(
          document.namespaceDeclaration().qualifiedIdentifier().value);
      } else {
        setCurrentNamespace("");
      }
  
      setCurrentImports(document.importDeclarations());
      NamedDataSchema schema = parseNamedType(document.namedTypeDeclaration());
      topLevelSchemas.add(schema);
      return schema.getFullName();
    }
docs: Parse list of Data objects.
  
  The {{DataSchema}'s parsed are in {{#topLevelDataSchemas}.
  Parse errors are in {{#errorMessageBuilder} and indicated
  by {{#hasError()}.
  
  @param document provides the source code in AST form