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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 write_vcpu_struct_field(self, field_name, value, x, y, p):
 """Write a value to the VCPU struct for a specific core. Parameters field_name : string Name of the field to write (e.g. `"user0"`) value : Value to write to this field. """

        field, address, pack_chars = \
            self._get_vcpu_field_and_address(field_name, x, y, p)

        # Pack the data
        if b"s" in pack_chars:
            data = struct.pack(pack_chars, value.encode('utf-8'))
        elif field.length == 1:
            data = struct.pack(pack_chars, value)
        else:
            # NOTE: At the time of writing no VCPU struct fields are of this
            # form.
            data = struct.pack(pack_chars, *value)  # pragma: no cover

        # Perform the write
        self.write(address, data, x, y)