public java.lang.String getContentType() {
      java.lang.Object ref = contentType_;
      if (!(ref instanceof java.lang.String)) {
        com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
        java.lang.String s = bs.toStringUtf8();
        contentType_ = s;
        return s;
      } else {
        return (java.lang.String) ref;
      }
    }
<pre>
Optional. Updates objects Content-Type fixed metadata. Unset values will be
ignored.
 Set empty values to clear the metadata. Refer to documentation in
 https://cloud.google.com/storage/docs/metadata#content-type
</pre>

<code>optional string content_type = 4 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The contentType.
java-storagebatchoperations/proto-google-cloud-storagebatchoperations-v1/src/main/java/com/google/cloud/storagebatchoperations/v1/PutMetadata.java