code: function insertDisplayName(path, id) {
      const assignment = t.assignmentExpression(
        '=',
        t.memberExpression(
          t.identifier(id),
          t.identifier('displayName')
        ),
        t.stringLiteral(id)
      )
      // Put in the assignment expression and a semicolon
      path.insertAfter([assignment, t.emptyStatement()])
    }
docs: Insert a static displayName for the identifier