I actually ran into the same thing again, when I needed to copy a file from
Netty's tests (an abstract test base class) and was not quite sure what 4d)
under the ASL 2.0 meant:
4. Redistribution. You may reproduce and distribute copies of the Work or
Derivative Works thereof in any medium,
In several locations we have copied code from external projects, for
example
flink-scala-shell/src/main/java/org/apache/flink/api/java/JarHelper.java
links to the file from org.apache.xmlbeans/xmlbeans/2.4.0. We also have
copied from Apache's Calcite, Spark, and Hadoop.
None of these projects are
