public Struct put(String fieldName, Object value) {
        Field field = lookupField(fieldName);
        return put(field, value);
    }
Set the value of a field. Validates the value, throwing a {@link DataException} if it does not match the field's
{@link Schema}.
@param fieldName the name of the field to set
@param value the value of the field
@return the Struct, to allow chaining of {@link #put(String, Object)} calls
connect/api/src/main/java/org/apache/kafka/connect/data/Struct.java