code: function checkReference(references) {
              astUtils.getModifyingReferences(references).forEach(reference => {
                  context.report({ node: reference.identifier, message: "'{{name}}' is a function.", data: { name: reference.identifier.name } });
              });
          }
docs: Reports a reference if is non initializer and writable.
  @param {References} references - Collection of reference to check.
  @returns {void}