in extension-base/src/main/java/com/azure/autorest/extension/base/model/codemodel/KnownMediaType.java [96:106]
public String getContentType() {
switch (this) {
case BINARY: return "application/octet-stream";
case FORM: return "application/x-www-form-urlencoded";
case JSON: return "application/json";
case MULTIPART: return "multipart/form-data";
case TEXT: return "text/plain";
case XML: return "application/xml";
default: return JSON.getContentType();
}
}