public Builder setUnreachable(int index, java.lang.String value) {
      if (value == null) {
        throw new NullPointerException();
      }
      ensureUnreachableIsMutable();
      unreachable_.set(index, value);
      bitField0_ |= 0x00000004;
      onChanged();
      return this;
    }
<pre>
Locations that could not be reached.
</pre>

<code>repeated string unreachable = 3;</code>

@param index The index to set the value at.
@param value The unreachable to set.
@return This builder for chaining.
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/ListNodesResponse.java