private void ensureErrorDetailsIsMutable() {
        if (!errorDetails_.isModifiable()) {
          errorDetails_ = new com.google.protobuf.LazyStringArrayList(errorDetails_);
        }
        bitField0_ |= 0x00000002;
      }
<pre>
Required. A URL that refers to the target (a data source, a data sink,
or an object) with which the error is associated.
</pre>

<code>string url = 1 [(.google.api.field_behavior) = REQUIRED];</code>

@param value The bytes for url to set.
@return This builder for chaining.
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java