Usage with 'http' (HTTPie):
    http http://api.x3dna.org/fiber/help    # display this help message
    http http://api.x3dna.org/fiber/list    # show a list of available fiber models (56 in total)
    http http://api.x3dna.org/fiber/str_id  # build model 'str_id' in the range of [1, 56]
    http http://api.x3dna.org/fiber/name    # generate a model with common names as shown below:
              A-DNA, B-dna, C_DNA, D-DNA, ZDNA, RNA, RNAduplex, PaulingTriplex, G4
              Case does not matter, and the separator can be '-' or '_' or omitted.
              So a-dna, A-dNA, a_DNA, or ADNA is valid for building an A-DNA model.

Options (via query strings, or form fields):
    seq=base-sequence # A, C, G, T, U for generic model
    repeat=number     # number of repeats of the sequence
    cif=1             # output file in mmCIF format

Examples with 'http' (HTTPie):
    http http://api.x3dna.org/fiber/1       # model no. 1 (i.e., calf thymus A-DNA model)
    http -f http://api.x3dna.org/fiber/1 seq=A3TTT repeat=2  # specific sequence, repeated twice
    http http://api.x3dna.org/fiber/rna     # single-stranded RNA model
    http http://api.x3dna.org/fiber/rna-ds  # double-stranded RNA model
    http http://api.x3dna.org/fiber/pauling # the triplex model of Pauling & Corey
    http http://api.x3dna.org/fiber/g4      # G-quadruplex model
    # with 'curl'
    curl http://api.x3dna.org/fiber/1
    curl http://api.x3dna.org/fiber/1 -d 'seq=A3TTT' -d 'repeat=2'
    curl http://api.x3dna.org/fiber/rna
    curl http://api.x3dna.org/fiber/rna-ds
    curl http://api.x3dna.org/fiber/pauling
    curl http://api.x3dna.org/fiber/g4