code: def isspmatrix_dia(x):
      """Checks if a given matrix is of DIA format.
  
      Returns:
          bool: Returns if ``x`` is :class:`cupyx.scipy.sparse.dia_matrix`.
  
      """
      return isinstance(x, dia_matrix)
  
file_path: cupy/cupyx/scipy/sparse/_dia.py
imports: import cupy
  from cupy import _core
  from cupyx.scipy.sparse import _csc
  from cupyx.scipy.sparse import _data
  from cupyx.scipy.sparse import _util
label_desc: Use image node_id 1 for calling a global function with example usage: isspmatrix_dia(x) and returns: isinstance