fn get_certificate(
env: soroban_sdk::Env,
cert_id: soroban_sdk::String,
) -> Option
fn issue_certificate(
env: soroban_sdk::Env,
issuer: soroban_sdk::Address,
cert_id: soroban_sdk::String,
student_name: soroban_sdk::String,
course_name: soroban_sdk::String,
cert_hash: soroban_sdk::String,
) -> soroban_sdk::Symbol
fn revoke_certificate(
env: soroban_sdk::Env,
issuer: soroban_sdk::Address,
cert_id: soroban_sdk::String,
) -> soroban_sdk::Symbol
fn verify_certificate(env: soroban_sdk::Env, cert_id: soroban_sdk::String) -> bool