docs: public static boolean isPositiveDefinite( ZMatrixRMaj A ) {
          if( A.numCols != A.numRows)
              return false;
  
          CholeskyDecompositionInner_ZDRM chol = new CholeskyDecompositionInner_ZDRM(true);
          if( chol.inputModified() )
              A = A.copy();
  
          return chol.decompose(A);
      }