class_docstr: BaseClass for variant callers.
class_docstr_tok: ["BaseClass","for","variant","callers","."]
code: def __init__(self, options, use_cache_table, max_cache_coverage):
      self.options = options
      self.cpp_variant_caller = (
          variant_calling_multisample.VariantCaller(self.options)
      )
      self.cpp_variant_caller_from_vcf = variant_calling.VariantCaller(
          self.options
      )
  
      self.max_cache_coverage = max_cache_coverage
      # pylint: disable=g-complex-comprehension
      if use_cache_table:
          self.table = [
              [
                  self._calc_reference_confidence(n_ref, n_total)
                  for n_ref in range(n_total + 1)
              ]
              for n_total in range(self.max_cache_coverage + 1)
          ]
      else:
          self.table = None
  
imports: import abc
  import collections
  import itertools
  import math
  import operator
  import statistics
  from typing import Dict, Sequence, Tuple
  import numpy
  from deepvariant.protos import deepvariant_pb2
  from deepvariant.python import allelecounter
  from deepvariant.python import variant_calling
  from deepvariant.python import variant_calling_multisample
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.util import genomics_math
  from third_party.nucleus.util import variantcall_utils
  from third_party.nucleus.util import vcf_constants
label_desc: Use image node_id 1 to create a new VariantCaller object  with example: obj = VariantCaller(options, use_cache_table, max_cache_coverage)