public Builder clearMasterIpv4CidrBlock() {
      masterIpv4CidrBlock_ = getDefaultInstance().getMasterIpv4CidrBlock();
      bitField0_ = (bitField0_ & ~0x00000004);
      onChanged();
      return this;
    }
<pre>
Optional. The /28 network that the masters will use.
</pre>

<code>string master_ipv4_cidr_block = 3 [(.google.api.field_behavior) = OPTIONAL];</code>

@return This builder for chaining.
java-telcoautomation/proto-google-cloud-telcoautomation-v1/src/main/java/com/google/cloud/telcoautomation/v1/FullManagementConfig.java