Data generated by editing https://github.com/ValkyrieSystems/sarkit/blob/main/data/example-cphd-1.1.0.xml and using the following python code;

```python
from pathlib import Path

import lxml.etree

import numpy as np
import sarkit.cphd as skcphd


xmltree = lxml.etree.parse("example.xml")
first_channel = xmltree.find("{*}Data/{*}Channel")
ch_id = first_channel.findtext("{*}Identifier")
num_v = int(first_channel.findtext("{*}NumVectors"))
num_s = int(first_channel.findtext("{*}NumSamples"))
sig_format = xmltree.findtext("{*}Data/{*}SignalArrayFormat")


meta = skcphd.Metadata(
    xmltree=xmltree,
    file_header_part=skcphd.FileHeaderPart(additional_kvps={"K": "V"}),
)

sig = np.zeros((num_v, num_s), dtype=skcphd.binary_format_string_to_dtype(sig_format))
pvps = np.zeros(num_v, dtype=skcphd.get_pvp_dtype(xmltree))

with Path("example.cphd").open("wb") as f, skcphd.Writer(f, meta) as w:
    w.write_signal(ch_id, sig)
    w.write_pvp(ch_id, pvps)
```

The XML used inside `test.cphd` is not valid CPHD XML and has been edited to reduce size.