How do you troubleshoot "already consumed" builder exceptions in Axiom?

This class of error almost always traces back to one of two root causes: calling serializeAndConsume() more than once on the same tree, or attempting to navigate/serialize a tree after its underlying XMLStreamReader has already been closed or fully drained by an earlier operation.

1. Check whether serializeAndConsume() is called more than once, directly or indirectly, on the same element - if the tree needs to be written out more than once, switch to serialize() instead, which caches nodes and leaves the tree reusable.
2. Check for premature close() calls on the builder or reader, especially in code with early-return branches or exception handling that might close a resource before all intended navigation has actually happened.
3. Check for concurrent access - two threads sharing the same builder or tree can race to consume the same underlying stream, since Axiom's default implementation isn't synchronized for this kind of shared mutation.
4. If the tree genuinely needs to be read, modified, and then read again, consider calling build() explicitly up front to fully materialize it into an independent, stream-free structure before further processing.

A useful diagnostic habit is adding a clear comment or a small wrapper at every call site that uses serializeAndConsume(), explicitly noting that the tree becomes unusable afterward - most instances of this bug come from a later code change adding a second read or write path without realizing the first one had already consumed the stream.