message: Implement PropertyList::len()
diff: @@ -2,7 +2,7 @@ use std::fmt::{self, Debug};
  use std::ops::Deref;
  use std::ptr;
  -use libhdf5_sys::h5p::{H5Pcopy, H5Pequal, H5Pexist, H5Piterate};
  +use libhdf5_sys::h5p::{H5Pcopy, H5Pequal, H5Pexist, H5Pget_nprops, H5Piterate};
  use crate::internal_prelude::*;
  @@ -151,6 +151,10 @@ impl PropertyList {
  h5lock!(H5Piterate(self.id(), ptr::null_mut(), Some(callback), data_ptr));
  data
  }
  +
  + pub fn len(&self) -> usize {
  + h5get_d!(H5Pget_nprops(self.id()): size_t)
  + }
  }
  #[cfg(test)]
  