public Builder addAllOutputIndex(java.lang.Iterable<? extends java.lang.Integer> values) {
      ensureOutputIndexIsMutable();
      com.google.protobuf.AbstractMessageLite.Builder.addAll(values, outputIndex_);
      bitField0_ |= 0x00000008;
      onChanged();
      return this;
    }
<pre>
Output only. The index that locates the explained prediction output.

If the prediction output is a scalar value, output_index is not populated.
If the prediction output has multiple dimensions, the length of the
output_index list is the same as the number of dimensions of the output.
The i-th element in output_index is the element index of the i-th dimension
of the output vector. Indices start from 0.
</pre>

<code>repeated int32 output_index = 4 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

@param values The outputIndex to add.
@return This builder for chaining.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Attribution.java