code: public void setKeyword(com.google.api.ads.adwords.axis.v201809.cm.Keyword keyword) {
          this.keyword = keyword;
      }
docs: Sets the keyword value for this KeywordEstimateRequest.
  
  @param keyword   * The {@link Keyword} to estimate. The keyword text is required
  regardless
  of whether the keyword ID is included. The keyword
  ID is optional and has
  the following characteristics:
  <ul>
  <li>When omitted, the ID indicates a new keyword
  to be estimated.</li>
  <li>When present with a campaign and ad group
  also specified, the ID should
  be for an existing keyword in the ad group. This
  can improve the estimates
  since historical performance is known.</li>
  <li>When present without a campaign and ad group
  specified, the ID is
  ignored.</li>
  </ul>
  <span class="constraint Required">This field is
  required and should not be {@code null}.</span>