openrtb-core/src/main/java/com/google/openrtb/json/OpenRtbJsonUtils.java
public static void writeIntBoolField(String fieldName, boolean data, JsonGenerator gen)
      throws IOException {
    gen.writeNumberField(fieldName, data ? 1 : 0);
  }
public static void writeIntBoolField(String fieldName, boolean data, JsonGenerator gen)
      throws IOException {
    gen.writeNumberField(fieldName, data ? 1 : 0);
  }
Writes a boolean as int, where false = 0 and true = 1.