@java.lang.Override
        public StreamingSynthesizeConfig parsePartialFrom(
            com.google.protobuf.CodedInputStream input,
            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
            throws com.google.protobuf.InvalidProtocolBufferException {
          Builder builder = newBuilder();
          try {
            builder.mergeFrom(input, extensionRegistry);
          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
            throw e.setUnfinishedMessage(builder.buildPartial());
          } catch (com.google.protobuf.UninitializedMessageException e) {
            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
          } catch (java.io.IOException e) {
            throw new com.google.protobuf.InvalidProtocolBufferException(e)
                .setUnfinishedMessage(builder.buildPartial());
          }
          return builder.buildPartial();
        }
<pre>
Optional. The pronunciation customizations are applied to the input. If
this is set, the input is synthesized using the given pronunciation
customizations.

The initial support is for en-us, with plans to expand to other locales in
the future. Instant Clone voices aren't supported.

In order to customize the pronunciation of a phrase, there must be an exact
match of the phrase in the input types. If using SSML, the phrase must not
be inside a phoneme tag.
</pre>

<code>
.google.cloud.texttospeech.v1.CustomPronunciations custom_pronunciations = 5 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/StreamingSynthesizeConfig.java