public Builder clearHashPrefix() {
      bitField0_ = (bitField0_ & ~0x00000001);
      hashPrefix_ = getDefaultInstance().getHashPrefix();
      onChanged();
      return this;
    }
<pre>
A hash prefix, consisting of the most significant 4-32 bytes of a SHA256
hash. For JSON requests, this field is base64-encoded.
Note that if this parameter is provided by a URI, it must be encoded using
the web safe base64 variant (RFC 4648).
</pre>

<code>bytes hash_prefix = 1;</code>

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