in ecs-logging-core/src/main/java/co/elastic/logging/EcsJsonSerializer.java [174:192]
public static void serializeOrigin(StringBuilder builder, String fileName, String methodName, int lineNumber) {
builder.append("\"log\":{");
builder.append("\"origin\":{");
builder.append("\"file\":{");
builder.append("\"name\":\"");
JsonUtils.quoteAsString(fileName, builder);
builder.append('"');
if (lineNumber >= 0) {
builder.append(',');
builder.append("\"line\":");
builder.append(lineNumber);
}
builder.append("},");
builder.append("\"function\":\"");
JsonUtils.quoteAsString(methodName, builder);
builder.append('"');
builder.append("}");
builder.append("},");
}