H5G_CREATE1 creates a new group with the specified name at the specified location,
loc_id may be a file, group, dataset, named datatype or attribute. If an attribute, dataset, or named datatype is specified for
loc_id then the group will be created at the location where the attribute, dataset, or named datatype is attached. The name,
name, must not already be taken by some other object and all parent groups must already exist.
name can be a relative path based at
loc_id or an absolute path from the root of the file. Use of this function requires that any intermediate groups specified in the path already exist.
The length of a group name, or of the name of any object within a group, is not limited.
size_hint is a hint for the number of bytes to reserve to store the names which will be eventually added to the new group. Passing a value of zero for
size_hint is usually adequate since the library is able to dynamically resize the name heap, but a correct hint may result in better performance. If a non-positive value is supplied for
size_hint, then a default size is chosen.
The return value is a group identifier for the open group. This group identifier should be closed by calling H5G_CLOSE when it is no longer needed.
See H5G_CREATE_ANON for a discussion of the differences between H5G_CREATE1 and H5G_CREATE_ANON.