class_docstr: This is the R_k gate of the QTF.
class_docstr_tok: ["This","is","the","R_k","gate","of","the","QTF","."]
code: def targets(self):
      return self.label[:1]
  
imports: from sympy.core.expr import Expr
  from sympy.core.numbers import I, Integer, pi
  from sympy.core.symbol import Symbol
  from sympy.functions.elementary.exponential import exp
  from sympy.matrices.dense import Matrix
  from sympy.functions import sqrt
  from sympy.physics.quantum.qapply import qapply
  from sympy.physics.quantum.qexpr import QuantumError, QExpr
  from sympy.matrices import eye
  from sympy.physics.quantum.tensorproduct import matrix_tensor_product
  from sympy.physics.quantum.gate import Gate, HadamardGate, SwapGate, OneQubitGate, CGate, PhaseGate, TGate, ZGate
  from sympy.functions.elementary.complexes import sign
label_desc: Use image node_id 4 for calling the RkGate obj's underlying member method code with example usage: obj.targets() and returns: self