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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_vcpu_field_and_address(self, field_name, x, y, p):
 """Get the field and address for a VCPU struct field."""

        vcpu_struct = self.structs[b"vcpu"]
        field = vcpu_struct[six.b(field_name)]
        address = (self.read_struct_field("sv", "vcpu_base", x, y) +
                   vcpu_struct.size * p) + field.offset
        pack_chars = b"<" + field.pack_chars
        return field, address, pack_chars