public Builder clearUsername() {
          username_ = getDefaultInstance().getUsername();
          bitField0_ = (bitField0_ & ~0x00000001);
          onChanged();
          return this;
        }
<pre>
Required. The user name of the custom account.
</pre>

<code>string username = 1;</code>

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