class_docstr: Class for reading from native VCF files.
  
  Most users will want to use VcfReader instead, because it dynamically
  dispatches between reading native VCF files and TFRecord files based
  on the filename's extensions.
class_docstr_tok: ["Class","for","reading","from","native","VCF","files",".","Most","users","will","want","to","use","VcfReader","instead",",","because","it","dynamically","dispatches","between","reading","native","VCF","files","and","TFRecord","files","based","on","the","filename","'s","extensions","."]
code: def __exit__(self, exit_type, exit_value, exit_traceback):
      self._reader.__exit__(exit_type, exit_value, exit_traceback)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from third_party.nucleus.io import genomics_reader
  from third_party.nucleus.io import genomics_writer
  from third_party.nucleus.io.python import vcf_reader
  from third_party.nucleus.io.python import vcf_writer
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.util import ranges
  from third_party.nucleus.util import variant_utils
  from third_party.nucleus.util import vcf_constants
label_desc: Use image node_id 4 for calling the NativeVcfReader obj's underlying member method code with example usage: obj.__exit__(exit_type, exit_value, exit_traceback) without return types