Discrete DLR builder

function build(dlrGrid, print::Bool = true) Construct discrete Lehmann representation

#Arguments:

• dlrGrid: struct that contains the information to construct the DLR grid. The following entries are required: Λ: the dimensionless scale β*Euv, rtol: the required relative accuracy, isFermi: fermionic or bosonic, symmetry: particle-hole symmetry/antisymmetry or none
• print: print the internal information or not

function preciseKernelT(dlrGrid, τ, ω, print::Bool = true)

Calculate the kernel matrix(τ, ω) for given τ, ω grids

Arguments

• τ: a CompositeChebyshevGrid struct or a simple one-dimensional array
• ω: a CompositeChebyshevGrid struct or a simple one-dimensional array
• print: print information or not