private static Schema commonSchemaForFloat32(Schema previous, Schema newSchema, Type newType) {
        if (newType == Type.INT8 || newType == Type.INT16 || newType == Type.INT32 || newType == Type.INT64) {
            return previous;
        } else if (newType == Type.FLOAT64) {
            return newSchema;
        }
        return null;
    }
Merge two schemas to a common schema which can represent values from both input schemas.
@param previous One Schema, non-null
@param newSchema Another schema, non-null
@return A schema that is a superset of both input schemas, or null if no common schema is found.
connect/api/src/main/java/org/apache/kafka/connect/data/Values.java