  Gamma-ray bursts (GRBs) are divided into short gamma-ray bursts (SGRBs) and
long gamma-ray bursts (LGRBs) based on the bimodal distribution of their
durations. LGRBs and SGRBs are typically characterized by different statistical
characteristics. Nevertheless, there are some samples that challenge such a
framework, such as GRB 060614, a long-duration burst with short-burst
characteristics. Furthermore, GRBs are generally considered to be an event with
no periodic or repetitive behavior, since the progenitors usually undergo
destructive events, such as massive explosions or binary compact star mergers.
In this work, we investigated Fermi data for possible quasiperiodic
oscillations and repetitive behaviors of GRBs using timing analysis methods and
report a special event GRB 201104A, which is a long-duration burst with the
characteristics of an SGRB, and it exhibits a "repetitive" behavior. We propose
that such a situation may arise from lensed SGRBs and attempt to verify it by
Bayesian inference. In addition, we extend the spectral analysis to Bayesian
inference. In spite of the existence of at least two distinct time periods with
a nearly identical spectrum, there is no strong evidence that they result from
a lensing GRB. Taking the gravitational-lensing scenario out of consideration,
a long burst would resemble a short burst in its repetitive behavior, which
presents a challenge for the current classification scheme.
