@java.lang.Override
  public boolean equals(final java.lang.Object obj) {
    if (obj == this) {
      return true;
    }
    if (!(obj instanceof com.google.cloud.vertexai.api.Citation)) {
      return super.equals(obj);
    }
    com.google.cloud.vertexai.api.Citation other = (com.google.cloud.vertexai.api.Citation) obj;

    if (getStartIndex() != other.getStartIndex()) return false;
    if (getEndIndex() != other.getEndIndex()) return false;
    if (!getUri().equals(other.getUri())) return false;
    if (!getTitle().equals(other.getTitle())) return false;
    if (!getLicense().equals(other.getLicense())) return false;
    if (hasPublicationDate() != other.hasPublicationDate()) return false;
    if (hasPublicationDate()) {
      if (!getPublicationDate().equals(other.getPublicationDate())) return false;
    }
    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
    return true;
  }
<pre>
Output only. Publication date of the attribution.
</pre>

<code>.google.type.Date publication_date = 6 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Citation.java